Guppies make unassuming pets, but in the wild they adopt a daring and counterintuitive tactic to avoid becoming dinner. When they spot a predator, they suddenly darken their eyes from silver to jet ...

Guppies are a small, pretty species of fish that are extremely popular for home aquariums. While they’re fun in captivity, in the wild they can cause major trouble. Native to South America, guppies ...

Guppies can be fooled by optical illusions into believing objects are smaller or larger than they really are. This suggests they might not always make the best choices in their natural environment.

A properly dressed male guppy, with its gaudy blue spots and brilliant splashes of orange, can't help but stand out. But for a fish that spends its life swimming among predators, it seems that good ...