Next, be certain that you have or can afford to purchase or build an enclosure of appropriate size for the animal you wish to keep. This will require some research, as some species have very modest needs, while others require very elaborate setups in order to do well. As a rule, desert species prefer a long, low setup, as do most semi-aquatic frogs and terrestrial species. Arboreal species prefer a tall setup, and species which spend equal amounts of time climbing, walking, and swimming require considerable space in all dimensions. In general, species that require a high humidity do better in closed off environments such as a glass or plastic tank, which helps keep the moisture in. However, some tropical rainforest species have very exacting requirements for a very high humidity combined with excellent ventilation: This is true of many chameleon species. These species do best in completely open or mesh enclosures. Species with higher temperature requirements may also do better in more closed off cages, so as to retain heat.
One of the things to look for in a good enclosure is construction: (is it made of appropriate materials for the environment you wish to put in it, ie, sealed against rot if it will be exposed to high humidity? Will it withstand the attention of a very strong animal? Will it prevent injury to claws, toes, and noses?). Wire mesh cages should be plastic-coated, and screen can catch claws. A cage without a tightly locking lid might allow a strong snake or monitor to escape. Be sure that the materials the cage is made of are non-toxic, and will not release toxic fumes if exposed to high heat or moisture.
Another thing to look for in an enclosure is ease of cleaning. It should be non-porous, so that wastes cannot soak in where they can't be cleaned out again. All exposed surfaces should be accessable so that they can be washed and sterilized. There should be no crevices, cracks, or joints that would allow wastes to seep in, insects or mites to hide, or fungi and bacteria to grow. Perching branches and decorations should be removeable for cleaning, or replacement.
Is your enclosure designed with display of the animal in mind? If so, can you decorate it attractively and see the animal within it clearly? Enclosures not meant for display may be as simple as a ventilated sweater box of appropriate size.
Once you have your enclosure set up, next you must be certain that you have the necessary equipment to maintain temperature and humidity. Reptiles and amphibians are ectotherms. This means that they cannot regulate their own body temperature internally. The euphemism "cold-blooded" has probably cost many herps their lives over the years, as people assume that the animals are happy at room temperature, and not bothered by the cold. In reality, herps DO regulate their body temperatures...they simply do so externally. To warm up, they bask in the sun or seek out warmer areas, and to cool down, they retreat to shade or water, or burrow, depending on the species. Most herps have an optimal temperature range which they seek to maintain. Our body temperature is kept at around 98.6 degrees farenheit. This temperature is what some species of herps also seek to maintain...others prefer a body temperature cooler or even warmer than this. If a herp cannot regulate its temperature and maintain it at the proper level, then it will be unable to properly digest its food and behave normally.
This is where research on the species you wish to acquire is again essential. You must learn what the daytime and nighttime temperatures are in the area where that species lives, and then you must duplicate them in its captive environment. You should also create a temperature gradient within the cage: that is, one area very warm, while another is cooler. This allows the animal to move around the cage to maintain its ideal temperature. Most common pet species do well with a gradient that ranges from around 75 to 80 degrees farenheit on the cool side to 95 in the warmest spot. However, some species such as green iguanas and uromastix need a hot spot of well over 100 degrees farenheit, while montane species such as Jackson's chameleons will succomb to heat stress if temperatures rise above 80 degrees or so. If you plan to keep a montane or other cool environment species, be sure that your average room temperatures are low enough to accomodate its needs. It may require its own air conditioning unit.
In order to maintain these temperatures, you will need to acquire heating equipment. A variety of choices are available. Perhaps the best for most diurnal (active during the day) species is a heat lamp. You can purchase a simple metal clamp lamp at a hardware store. Be sure it has a ceramic fixture to withstand high heat. A reptile "day" bulb can be purchased from a pet store. These bulbs duplicate uva light, so that the color is natural, and they may cause animals to behave more naturally and be more active than an ordinary bulb. There are also red and blue lights available which can provide heating for nocturnal species without disturbing their activities. The color of the light does not trigger them to believe it is daytime. The lamp should be placed over top of the enclosure, on a non-flammable surface, on one side of the cage so that a heat gradient is created. Lamps should always be placed outside the enclosure to prevent burns.
In addition to heat lamps, there are also undertank heaters, heat strips, and various types of hot rocks. Undertank heaters are excellent to supplement a heat lamp or provide sole heat for a nocturnal species, as are heat strips. They can be placed under one side of the enclosure. They also should not be placed inside the enclosure. Hot rocks seem convenient, but can be extremely dangerous, and are the least recommended source of heating. For one thing, they do not heat the enclosure. Reptiles are required to sit on the rock itself in order to warm up, and cool down again as soon as they move off. Additionally, if the thermostat within the rock is faulty, or wears out over time, the rock may overheat. This has caused many terrible tragedies among reptile keepers. Reptiles do not have skin which is very sensitive to temperature. Instead, they have a light sensitive organ on top of their head known as the "third eye", which allows them to judge heat and light from the sun. Thus, if the rock overheats, the reptile may not realize that it is being burned until it is far too late. Reptiles have been killed this way, and a great many dreadful injuries have occurred.
If you MUST use a hot rock, replace it once every year, and monitor its temperature on a daily basis. Some people have attempted to help reduce the burn risk by placing a cloth around the rock. This has caused fires! It is not recommended by the manufacturer, and may actually increase burn risks in some cases. Additionally, some herps may ingest the cloth and this must be surgically removed (pythons are particularly well known for ingesting cloth). Hot rocks should never be used as a primary heat source, and should always be much larger than the reptile they are used with, to prevent it from being covered by the animal's body and concentrating the heat. While hot rock technology has improved over the years, they are STILL not a safe choice for providing heat for reptiles and amphibians. The most ideal form of heat for herps is an overhead heat lamp: This is closest to what they have evolved to use, and allows them to thermoregulate in the most natural possible fashion.
Next, all diurnal species will require a flourescent UVB-producing light, and some nocturnal species may benefit from it as well. Special reptile light bulbs are sold in pet stores for this purpose. Pay attention to the amount of UVB radiation produced by the bulb. With these lights, the higher the better, as none of them can come close to duplicating the level found in natural sunlight. UVA radiation, produced by the reptile heat bulbs, is not enough. It must be UVB, currently produced only by special flourescent bulbs. The importance of these bulbs cannot be overstressed. For some species, such as green iguanas and uromastix, they are absolutely essential, and even supplements cannot be used to override the need for this lighting. UVB radiation is used by reptiles to produce vitamin D3. This essential nutrient is used in the calcium metabolism, and without it herps develop metabolic bone disease ("rubber jaw"). Their bones become soft and brittle, and they eventually die from lack of utilizable calcium in their system. This light should be placed over the enclosure, with a basking area at a distance of less than one foot beneath it (preferably no more than 6 to 8 inches), and no glass or plastic between it and the reptile. (Wire mesh is best, screen can also reduce UVB). Diurnal reptiles are not well-equipped to derive vitamin D3 from dietary sources. Nocturnal reptiles can usually acquire what they need from their prey, as can snakes.
At least 2 thermometers should be used in the reptile enclosure. They should be placed inside, one at the level of the basking perch, the other in the coolest area of the enclosure. There are stick-on thermometers for reptiles available at pet stores. Use these to ensure that heating sources are set to the right temperatures, and are at the right distances from the enclosure to provide a proper heat gradient for your species. Set up heating and lighting BEFORE you bring your pet home, so that you have a proper environment ready for it and don't have to experiment after it arrives.
Now that heating and lighting are taken care of, humidity should be addressed. Desert species exposed to high humidity levels can develop respiratory infections. Tropical species kept too dry tend to have problems with shedding and mucous membranes. Proper humidity levels can be essential for herp health, and of course this is all the more true for amphibians, which usually require high levels of humidity to prevent dehydration.
For reduced humidity, use only a shallow water dish, and provide adquate ventilation. Make sure substrates stay completely dry, and clean, to prevent moisture buildup. In a dry climate, this is fairly easy to do, but keeping enclosure humidity levels down in a humid climate can be a challenge. Reptile hygrometers may be available at your local pet store, or via catalog or online. These will allow you to monitor the humidity level in the enclosure--simply place within the cage as you would a thermometer. Use a hygrometer whenever the humidity in an enclosure is a concern.
For increasing humidity in an enclosure, use a substrate which can safely be kept moist. Plain soil, shredded coconut fiber, bark chips, and mosses are all adequate choices. Attention must be paid to ensure that wastes are not allowed to collect in these substrates, for in a humid environment they will quickly mold, which can have serious health effects on your herps. They should be changed whenever they appear to be degrading, or immediately if they develop any sort of odor or appear soiled. Daily misting can be used to raise humidity levels, and some herps enjoy being misted. Many smaller herps also gain most of their drinking water from lapping dew, so misting can provide them with drinking water. For species like this, mist at least twice a day. A shallow bowl with a bubbling stone in it can also entice some dew-drinkers. Be careful that herps cannot fall into water sources where they might drown, and provide ample escape routes from the water if this is a concern. In-tank waterfalls are being sold now, and these can be a lovely addtion to a tropical setup, as well as increasing humidity levels. While expensive, the new ultrasonic foggers made for high humidity reptiles (or decorative fountains) are excellent for cleanly raising humidity levels. A very few delicate herps must be kept in a very high humidity environment with lots of ventilation and a DRY substrate. Read up carefully before you acquire your animal. If your animal's humidity requirements are significantly higher than the humidity of your local climate, purchase a hygrometer to monitor the enclosure.
Now that the basic environmental needs of your herp have been addressed, it's time to think about substrate and cage furnishings. In a non-display enclosure, newspaper is a very practical and safe substrate, and easy to clean. For desert reptiles, playground sand or calci-sand (made for reptiles) is the best choice. Other substrates pose a risk of impaction if they are ingested. Very fine sands can cause irritation. For tropical species, moss, coconut fiber, or bark chips work well, as does sterile plain soil (without vermiculite or perlite). Bad choices for herps include aquarium gravel, ground corn cob, very fine sands, or soils containing vermiculite and perlite. These all pose a risk to reptile which might accidently (or even purposefully) ingest them. Impactions can only be treated surgically, and only if caught very soon after they occur. Vermiculite and perlite particles seem to resemble food to some herptiles. Other substrates can stick to food items, causing them to be ingested accidently. Corn cob swells when moistened, so it poses a very serious risk.
Branches should be clean, and free of very rough spots which could cause abrasians. Take care small twigs cannot snap off and cause punctures. Branches should be fastened in place securely, so they cannot be pushed over, or fall down and crush a herp. Rocks should also be secured in place, not stacked so that they might fall. If you use live plants, take care that they are not contaminated by pesticides or fungicides. It's a good idea to replace the soil they are potted in, if you purchase them. Plastic or other artificial plants should be free of parts which can come loose and be ingested. All should be able to be taken down and cleaned and sterilized.
A small, shallow water container works well for most reptiles, but those which like to submerse themselves or swim will need larger, deeper ones. Be sure that herps that go into the water can easily get back out again, and not become trapped. A cat litter pan can work very well for a good sized water container that goes into an enclosure, and it can easily be lifted out and cleaned. Be sure containers cannot be knocked over, which could wet down the substrate too much and cause mold to grow. Containers for water should be easy to clean and sterilize, and should be cleaned on at least a daily basis, as well as when they are soiled.
Now you have set up a suitable environment for your pet, so it's time to be sure that you have researched its dietary needs, and have the proper foods and supplements on hand for it. Most herps are insectivorous. The safest foods for them to eat are commercially or home-raised crickets, mealworms, and wax worms. These insects are deficient in some nutrients, so should be dusted with a calcium or calcium/D3 supplement. You may wish to alternate this with a multi-vitamin/mineral supplement. Both types of supplements can be purchased from a pet store or other supplier of pet products. Don't overdo supplements--shake some crickets with powder in a bag, or dust them lightly. Crickets and mealworms should be gutloaded. This means that you keep them for a day or so before you feed them to your herp, and feed them a nutritious diet. Many times, pet stores will not feed their crickets or mealworms while they are in the store, or will feed them a cheap food low in nutrition. By providing some fresh fruit or vegetable and some nutritious food, you ensure that rather than having an empty gut, they have a gut full of good food which your reptile will then ingest along with them. Several commercial cricket gutloading formulas are also available. Be sure that you do not over or under feed your herp. Some herps will eat enough to become obese, which can cause serious health issues. This is less of a problem with small insectivores than with large carnivores and omnivores. Remove any uneaten food items from its enclosure promptly. Stray crickets can and have attacked herps and bitten them badly, particularly if there is no other food or water for the crickets within the enclosure.
In addition to commercial food insects, you can also capture insects yourself to supplement your herps. Be aware that this increases the risk of parasite transmission. You must take extreme care that the wild insects you gather are non-toxic, and that there is no chance they have been exposed to pesticides or other harmful chemicals. However, greater variety in a herp's diet may well make it worthwhile to do this, so long as you take ample precautions. For larger herps, earthworms, pink mice or rats, and fish make good food items. They also carry some increased risk of parasite transmission. Goldfish are not a good food item, but tilapia, feeder guppies, and other feeder minnows are fine. Buying bait minnows from a bait and tackle store is not recommended, as these pose a very high parasite risk. Pink mice and rats should have their rump dipped in calcium powder before feeding, and should be offered only occasionally, as they are high in fat. Earthworms have an excellent nutrient balance. If you offer any of the higher risk food items, you should have a vet check your animal at least once a year for parasites.
Second most common after the insectivorous herps are the carnivorous herps. These animals, including primarily snakes and some monitors, tend to favor fish, other herps, birds, or mammals as prey. The safest food for a carnivorous herp is probably a commercially or home raised mouse or rat which has been pre-frozen and then thawed to room temperature before feeding. Contrary to popular belief, while some reptiles require the stimulus of movement in order to trigger their feeding instincts, the vast majority of snakes and monitors will accept dead prey items. You may need to work with them a while in order to train them to do so, but it is well worth your time. Dead mice do not fight back, and in an enclosed space, mice and rats can inflict serious or even deadly wounds on reptiles. Even knocking a prey item unconscious before feeding it is preferable to simply feeding live prey. Remember that you have a captive animal, it is not in a natural environment, nor should it be subject to laws of natural selection--you are responsible for its well-being. Freezing also reduces the risk of parasite transmission, and it means that you can stock up on prey items in quantity, and store them cleanly without odor or need to care for them. "Mice on ice" are commercially available now, pre-frozen and individually sealed against freezer burn. You can buy exactly the sizes and quantities you need. Be aware the some herps may be resistant to eating mice or rats at all. The animals at highest risk for rejecting these prey items include hatchling snakes of many species, and any imported snakes or herps. These animals may prefer very specific kinds of prey in the wild, and may be resistant to converting in captivity. If your carnivorous herp refuses mice or rats, and is otherwise healthy, you may need to try offering it the type of prey it would normally take in the wild. Once you have discovered what it will eat, you can begin the process of teaching it how to eat safer food items. You can, for example, rub a dead lizard over a pink mouse in order to give it the scent of a lizard. Once a herp has begun eating frozen thawed mice or rats, you've won that particular battle.
Least common among herps are the omnivorous and herbivorous animals. Among these are bearded dragons, blue-tongued skinks, green iquanas, and tortoises. Research your animal's dietary needs carefully. Too much protein or fat in the diet of an herbivore can be extremely harmful. Herbivorous reptile diets are more complex than simply throwing in some salad mix. Most vegetables grown for human consumption are low in the nutrients that herps need to stay healthy. You will have to pick and choose carefully to create a balanced diet for your herp. Commercial diets for herbivores and omnivores are currently in their infancy, and should be used only occasionally or as a supplement, and not as a primary source of nutrition. Never feed dog or cat food to any herptile. These foods are far too high in fat, and lack nutrients most herps need. Particularly detrimental is feeding these foods to any herbivore.
Check around for resources online and in books and magazines for lists of food combinations suitable for herbivorous and omnivorous herps. Be sure books and magazines are no more than 5 years past their publishing date, as advances in knowledge of reptile nutrition and care are very recent, and older publications may have outdated information which might be harmful. If preparing complex, mixed salads on a daily basis is not for you, then do not consider purchasing an herbivorous reptile such as a green iguana or tortoise. There are supplements designed to be sprinkled lightly over the salads of herbivores, so read their directions on doseages carefully.
Now that you have a complete enclosure, and have purchased or made arrangements for providing a proper diet for your pet, it's time to decide whether you will be getting a wild-caught or captive bred animal. Whichever you decide, you should have a veterinarian picked out. This should be a vet who has extensive experience with herps. Your local cat and dog doctor will not do. A wild caught animal should be seen by a vet as soon as possible after purchase. They invariably must be treated for parasites, and may have other problems as well. Wild animals which have undergone the stress of shipping may be in extremely poor health, even if it is not immediately apparent. Like birds, herps will hide their illness until they are on death's door, showing few symptoms to indicate that all is not well. By the time they appear ill, they are VERY ill. In contrast, a captive bred animal acquired from a reputeable breeder is most likely in fine health, and may need only an annual checkup to ensure that it stays that way. Take care with cb animals purchased from pet stores--they may have been housed in cages with animals which were wild-caught, or in cages which wild caught animals were previously housed and which were not sterilized afterward. Thus, though they may arrive in your home healthy, they may have picked up disease or parasites from the wild-caught animals, and should be monitored carefully and vetted. They may also have undergone a lot of stress while on display in the store, something which can reduce herps' immune function and appetite, so be aware of the relative tolerances of various species to stress before purchasing an animal from a pet store.
In conclusion, research is the key. Don't purchase an animal simply because it looks neat, if you have never heard of it before and are unsure of its requirements. Be sure you have all of its requirements met BEFORE you bring it home, and that you can afford to continue to meet them. Always judge an animal's suitability based on its ADULT size. Too many people purchase animals as babies, either not realizing what size they will reach when they grow up, or assuming that they will be able to give the animal away when it is larger. The reality is that zoos will not take these animals, and reptile rescues are absolutely full of half-grown pythons, green iguanas, and monitor lizards which outgrew their owners' capability to care for them. Herps will NOT slow or cease growing simply because their enclosure is too small. Ignore tales told by people who claim that they will not outgrow their cage. Tragically, most of these larger species die before they reach adulthood, due to the stress of being kept in too small an enclosure, or other aspects of improper care. Be certain that you know how long the species you intend to acquire will live. If you cannot afford to maintain the animal for its entire lifespan, do not purchase it.