Kids won't move out? Why not eat them

Kids these days: Can't get them to move out of the house, can't eat them.

Unless, that is, you're a sand goby or one of the many species of animals that occasionally snacks on its young.

New research has found a possible reason for parental cannibalism: Some offspring just take too long to grow up.

Normally, animals want to maximize the number of their offspring, so from an evolutionary standpoint such behaviour doesn't seem to make much sense.

But researchers noticed that sand gobies tend to eat the larger eggs, which take longer to hatch, because female sand gobies won't mate with males who are babysitting eggs. Researchers believe the fish fathers are trying to reduce the time spent caring for their young, allowing them to jump back into the mating season faster and thus produce more offspring overall.