Adult lobsters fight each other. That's why they put rubber bands on their claws In the lobster tank. *fun fact* Lobsters can be right or left handed (or clawed) just like people. One claw is shorter and thicker than the other and is used for crushing and fighting. The other is longer and thinner and used for grasping things. Some lobsters have their grasping claw on the left and others on the right.