If you place a rat in a maze with no food, the rat will simply run around the maze, familiarizing itself with the surroundings. If you then return the rat to the same maze the next day and add food, the rat will find the food much more quickly then will a rat placed in the maze with food for the first time. This is an example of latent learning. The rat has familiarized himself with a stimulus in the absence of any association with a positive or negative stimulus.
Many animals learn by imitation of conspecifics (same species animals). Macaques learn to wash sandy food by watching other members of the same species do the same. Another example of learning by imitation is the mobbing behavior of birds. European blackbirds mob predatory birds, such as owls, to chase away or perhaps kill the potential dangerous enemies. In an experiment to determine if this was a behavior learned by imitation, a naïve and experienced bird were each placed in view of each other, but separated by a glass partition. The experienced bird's enclosure contained an owl, and the naïve bird's enclosure contained another, harmless bird. Most of the enclosure was separated by an opaque partition, so that the naïve blackbird could not see the owl. When the experienced blackbird mobbed the owl, the naïve bird similarly mobbed the harmless bird. It appears that the naïve bird was learning its behavior from its conspecific; it did not know not to mob a harmless bird (see . A special case of imitation, known as cultural inheritance, occurs when one or more members of the population learn a novel behavior and that behavior spreads through the population by imitation. Perhaps the best evidence for cultural inheritance is that of a species of birds found in England, commonly known as great tits. In 1921, in England, milk bottles were still delivered to houses every morning. The bottles were sealed with tin foil. In that year, great tits in Southampton were first observed removing the tin foil and drinking the milk. In the 1930s and 1940s, the habit of opening and drinking the milk spread through England far too quickly to be accounted for by natural selection. Although it appears the behavior originated more than once, the most likely explanation is that the birds observed others opening the milk bottles, and then were able to do it themselves.