Tortoises: Testudinidae

Tortoises are known for their slow, lumbering movements on land. The males often fight among themselves, either by ramming their shells against one another or by biting at each other's legs. A male will also do the same things to a female in an attempt to convince her to mate with him. In addition, he will bob his head at her and chase her. Females lay from one to 51 eggs at a time. Each of the round or oblong eggs is about 1 to 2 inches (3 to 6 centimeters) in diameter and is typically quite brittle, or easily broken. Some females may not nest every year, but when they do, they may have more than one clutch, or nest of eggs, per season. Although scientists have not tested all of the species, the eggs in most become males or females based on the temperature of the nest. A particularly warm nest produces mostly females, and an especially cool one produces males. The eggs typically hatch in 100 to 160 days, but one species' eggs hatch only after 18 months. Some species may live 200 years or more.

Many tortoises become inactive in the summer when the weather is very dry. Many simply hide during the day in a shady spot, but some will dig a hole, or burrow, and spend the hottest part of the day there. On cooler days, some of these tortoises will seek out a warm spot and sunbathe, or bask, to increase their body temperature. Those species that live in colder climates may become inactive in the winter months.