Rabbits, rats, mice, hamsters and guinea pigs are social animals. Inappropriate housing or handling techniques can result in stress for the animal which shortens its life or result in aggressive behaviours when picked up or groomed.
Birds of all species, when caged, can exhibit anti-social behaviours, such as attention seeking, often feather plucking is seen in cases of parrots under stress.
Aggression in reptiles can be a difficulty for humans to live with, yet with the correct behaviour modification techniques such problems can be resolved.
All the above species are capable of being trained. It's simple, effective and enhances your realationship with your pet.