Each snake has various needs that must be met in order to keep it in good health in captivity. The following is an outline of factors that are important to the well-being of your pet. Most tropical species prefer the top half of that range, and most temperate zone snakes like the bottom half. A temperature gradient in the cage lets the snake decide how warm it wants to be. A thermometer can be the herper's best friend because a snake won't eat if it's more than a few degrees below optimum temperature.
Snakes have a day-night temperature cycle in the wild.
Some studies indicate that if a reptile is constantly held at optimum temperature for weeks, it suffers heat stress. Males also have the sperm killed. It is probably best for a snake to spend the night at a temperature 5 to 20 degrees Fahrenheit below its daytime activity temperature. Aquariums with pegboard tops make good cages. Plastic shoe boxes and storage boxes also make good cages after enough air holes have been cut in them.