There are a number of species of crayfish found in the United States living in a variety habitats. Some species live in wet meadows where they can burrow to below the water table. Some live in burrows on the shoreline of streams and lakes and some are entirely aquatic. They all need to wet their gills in order to breathe.

Seldom are they seen during the day since they are generally nocturnal. During daylight hours crayfish will hide under rocks in streams and ponds or in their burrows. Their presence is often indicated by mud chimneys along the shoreline formed by the spoil from their digging.
Red Swamp Crayfish from Burke Lake park  Burke, VA
Red Swamp Crayfish from Burke Lake park Burke, VA

Crayfish are omnivorous and will consume a variety of plant and animal materials. In the wild the bulk of their diet will consist of plant material and any microscopic creatures attached. The will also eat carrion, earthworms, small fish and occasionally each other. The lifespan of most crayfish is 1 to 3 years. Generally they breed in the spring . The female will carry a cluster of eggs numbering 12 to several hundred depending on the species, attached to the underside of her tail until they hatch .

It is not uncommon for a crayfish to lose one of its claws. If some other creature clamps onto a claw the crayfish has special muscles that allow the appendage to detach easily freeing the crayfish. It will then regenerate the lost limb although is will tend to be smaller than the one it is replacing.
Crayfish  IWLA Park Centreville, VA
This is an example of a crayfish that has lost its right claw and is in the process of growing a new one.