For two weeks every mating season, a male will mate as ... That little crustacean has proportionally the longest penis of any animal on earth spanning up to 10 times his body size.

Animals also choose their mates, sometimes with a great deal of care. Mating systems are important to understand because they reflect the result of natural selection on mate choice, and ultimately ...

Lemurs, lizards, whales — all are famed for their tails in some way. But which animal has the longest tail of all? In proportion to their bodies, grass lizards have the longest tails of any ...