One reason why more baby lobsters don't make it to adulthood? They tend to turn on each other. After hatching, lobsters go through numerous stages of development. Once they start to actually look like little lobsters, they're not just floating along and eating zooplankton, fish eggs and other types of larvae anymore. They're competing for food and going after prey like crab, gastropods, starfish and marine worms [source: St. Lawrence Global Observatory]. In close quarters, these juveniles will eat each other without any qualms. This behavior is part of why lobsters aren't often raised in captivity -- they have to be separated into individual containers [source: Anderson].
This cannibalistic behavior isn't limited to baby lobsters, though. It's common for adults to eat juveniles or lobsters that have just molted when they're in traps or tanks. Until recently, though, researchers hadn't witnessed this type of behavior in the wild. Then in 2012, scientists in Maine filmed lobsters practicing infanticide. They tethered a juvenile lobster, figuring that its natural predators, such as cod and skate, would take advantage. At night, though, adult lobsters fought over it. The cannibalism was blamed on a recent glut of lobsters. Warmer waters and overfishing practices had reduced the populations of their natural predators [source: Doucleff].