critics of zoos would argue that animals often suffer physically and mentally by being enclosed. even the best artificial environments can't come close to matching the space, diversity, and freedom that animals have in their natural habitats. this
deprivation causes many zoo animals to become stressed or mentally ill. capturing animals in the wild also causes much suffering by spitting up families. some zoos make animals behave unnaturally: for example, marine parks often force dolphins and whales to perform tricks. these mammals may die decades earlier than their wild relatives, and some even try to commit suicide.