When it comes to size, it's often, but not always, the case that larger species have a longer lifespan than smaller ones. For instance, an elephant or whale will live much longer than a mouse, rat, or vole, which in turn have years on flies and worms.

Why different animals have different lifespans?

Compared to larger animals, the cells inside a small animal are burning energy at a much higher rate. This high metabolic rate can cause biological wear and tear which, in turn, results in shorter lifespans.

Do all animals have the same life span?

One important factor is body size with larger animals, on average, living longer than smaller ones. In some species, environmental factors like temperature also influence how long animals live, with a lower body temperature generally being associated with a longer lifespan.