This genus of water bear is widespread and common. Their bodies are short, plump, and contain four pairs of limbs that are poorly articulated, a characteristic typical of soft-bodied animals. Each limb terminates in four to eight claws or discs. They lumber about in a slow bear-like gait over grains of sand and dirt or pieces of vegetation.
Most water bears feed on the fluids of plant and animal cells, but a few are predatory carnivores.
They are dioecious, having both male and female members, but the sexes are not distinct. One of the unique traits of water bears, and an obvious key to their survival, is their ability to reversibly suspend their metabolism, a condition called cryptobiosis.