The term terrarium refers to a closed transparent container (usually globe-shaped) in which plants are grown. They may also be used to house some small land animals, usually reptiles or amphibians, in which case they specifically need to be glass terrariums. Plant terrariums may be open, closed, or dish gardens. However, if it is home to any animal, the air supply cannot be cut off, thus the terrarium cannot be completely closed. Terrariums are made from clear glass or plastic; a common option is a large fish bowl. However, the containers used to build terrariums for reptiles are usually large fish tank-like glass containers with mesh screens that cover the top. Setting Up a Reptile Terrarium You must start with understanding what kind of habitat your pet needs. Please do a fair bit of research to understand their habitat in the wild, and then try your best to replicate it within the terrarium. The terrarium will vary depending on whether you have a lizard or snake as a pet. Know that some reptiles do well with artificial plants, while others benefit from real plants. One has to be careful about the selection of the plants, for the wrong kind can be harmful for your pet. While there are custom reptile terrariums, one need not feel compelled to buy one. If you are making your own, or trying to cut costs, the external structure can be an old aquarium. However, there are two very important points to keep in mind here; the first is that the aquarium should be in good condition with clear glass, and the second is that it should be big enough for your pet to comfortably move around in. Also, be aware that some reptiles, such as chameleons and small snakes, fare better in screen cages. You could also consider plywood and melamine containers, but take into account your pet's light, temperature, and humidity requirements before making the selection. If you plan to use an old aquarium, it is of critical importance for you to sterilize it first. After that, start laying the base. You need to follow instructions and directions available for this, as each species has its own requirements. The wrong kind of flooring can negatively impact the reptile's health. One usually puts in several layers of different materials, and you need to make different depths of different materials based on the species you're building for. A rule of thumb is an inch of sand, then an inch of pebbles, then sphagnum moss followed by several inches of soil. Once you know the ideal habitat for your pet, scour the market for materials that fit the bill. Find materials that you can use to create little caves and tunnels, which most reptiles enjoy. That apart, you may need rocks, vines, branches, etc., for the reptiles as well. If your pet is a ground dweller, gravel and rocks is okay, but for an arboreal (climbing) species, plants with branches are a must. For desert terrariums, substrates of sand, reptile carpet, or bark are used. Based on the reptile you have as a pet, you may need an aquatic terrarium, semi-aquatic terrarium, woodland terrarium or desert terrarium. As reptiles are cold-blooded creatures, some external source of heat (such as heat lamps) is essential in both small and large terrariums. If your pet lives in humid conditions in the wild, you may add a humidity source such as a fogger, waterfall, or bubbler. For reptiles a UVB heat and light source is necessary. Know that an ordinary light bulb can cause blindness in some reptiles. If all this seems too cumbersome, you can check reptile terrariums for sale, to find a suitable option.