THE EUSOCIAL ANIMALS

The Eusocial Animals

This page leads you to pages covering the diversity of eusocial animals, those with permanently sterile worker castes. These are mostly insects; the two exceptions are certain kinds of shrimp and the naked mole rats, burrowing mammals found in tropical and subtropical Africa. The evolution and behavior of eusocial animals provides many of the most complicated and intriguing puzzles in biology.

Do the workers in eusocial colonies give up their reproductive capacity willingly, as a a result of natural selection which favors helping over reproduction? Or, do their own parents rob them of their reproductive capacity in order to create unwilling workers? Once permanent sterilility is established, these animals have no option, in terms of gaining fitness, but to become workers and to help in their parent's nest.

Many other birds and mammals have life histories in which young serve as "helpers at the nest"; instead of attempting to establish their own nest and reproduction (for more on this type of helping,, see the section on "Cooperation among kin" at the beginning of this chapter). Eusociality and helping at the nest have the same evolutionary underpinnings, and may be thought of as points along a continuum of cooperation among relatives.

The links below lead to pages on each of the major kinds of eusocial animals. These, in turn, lead to pages dealing with the major properties of each kind of animal--diversity, caste, division of labor, communication, and reproduction.

Mammals

naked mole rats

Crustacea

shrimp

Insects