herpetarium (herp = reptile or amphibian) is an enclosure housing amphibians or reptiles. A serpentarium is a herpetarium for snakes. An insectarium is an enclosure for housing insects. When used to refer to a facility, it often refers to a facility that houses both insects and other invertebrates. A formicarium (formica = ant) or ant farm is an enclosure housing ants. Size and materials A vivarium is usually made from clear container (often plastic or glass). Unless it is an aquarium, it does not need to withstand the pressure of water, so it can also be made out of wood or metal, with at least one transparent side. Modern vivariums can be as simple as a bottle (see Bottle garden) and are sometimes constructed from epoxy-coated plywood and fitted with sliding glass doors. Coating the inside of a plywood vivarium helps to retain the natural effect of the environment. Epoxy-coated plywood vivariums retain heat better than glass or plastic enclosures and are able to withstand high degrees of humidity. They may be cubical, spherical, cuboidal, or other shapes. The choice of materials depends on the desired size and weight of the entire ensemble, resistance to high humidity, the cost and the desired quality. The floor of a vivarium must have sufficient surface area for the species living inside. The height can also be important for the larger plants, climbing plants, or for tree climbing animal species. The width must be great enough to create the sensation of depth, both for the pleasure of the spectator and the good of the species inside. The most commonly used substrates are common soil, small pebbles, sand, peat, chips of various trees, wood mulch, vegetable fibres (of coconut, for example), or a combination of these. The choice of the substrate depends on the needs of the plants or of the animals, moisture, the risks involved and aesthetic aspects. Sterile vivariums, sometimes used to ensure high levels of hygiene (especially during quarantine periods), generally have very straightforward, easily removable substrates such as paper tissue, wood chips and even newspaper. Typically, a low-nutrient, high-drainage substrate is placed on top of a false bottom or layer of expanded clay aggregate or stones, which retains humidity without saturating the substrate surface. Environmental controls Lighting A lighting system is necessary, always adapted to the requirements of the animal and plant species. For example, certain reptiles in their natural environment