Crow

One of the smiling animals on this list is the crow. Crows are noted for their cunning and their harsh, rasping caws. These fascinating birds can learn to imitate human vocal intonations. They also recall which individuals treated them well and which ones did not. Even more astounding is the fact that they transmit this knowledge down to their offspring.

Crows have been recorded pulling pranks on each other and engaging in complex forms of play, according to scientists. All for fun, they'll hang from trees, slide down inclines, and conceal stuff from each other.

Crows are gregarious and cooperative creatures. When they're not deceiving one another, they're teaching young crows important lessons. Male crows will roost together in a sort of bird bachelor pad before finding a mate.