It’s a "fish-fool-fish" world when you’re trying to get laid.
(Poecilia mexicana – the Atlantic molly fish)
When male Atlantic molly fish are trying to "hook up" with female mollies, they usually try to mate with the biggest female molly they see. But when other males are around, male mollies ignore the bigger females and pay attention to the smaller females. Why? Well, since male mollies tend to copy the mating choices of other males, this behavior deceives the rival fish into going after the female fish the male wasn’t interested in.