This is a discussion on My 20 Gal Tank within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
Originally Posted by Tobias168
Does Guppy's eat their own fry, ??
Yup, a good portion of fish will, if it fits in their mouth ...
Guppies will sometimes eat their own fry, but not reliably enough to keep the population under control. In a tank full of both sexes of guppies and nothing else, the guppy population will definitely increase over time until it reaches equilibrium.