An R-strategist is a type of animal that produces many offspring, all of which have a short life expectancy. The idea behind it is that the more offspring are produced, the greater the chances are of at least a few survivors. These animals evolved to do this because the environments they live in are generally unstable, and can change quickly. They are usually small animals who mature quickly and don’t care for their young. The millipede pictured here is an R-strategist animal.