Effects of early odor exposure in domestic chicks.

The effects of odor exposure during the last 2 days of incubation and immediately after hatching on subsequent responses by chicks to that same scent were assessed. When tested with an orange-treated and an unscented container, chicks that had been previously exposed to orange odor more rapidly approached both containers than did control chicks and spent more time near them. In both conditions, chicks spent significantly more time near the unscented container than the one treated with orange. In a second experiment, chicks previously exposed to orange odor and control chicks did not differ in their rates of locomotor activity or latency to approach stimulus containers when orange odor was not present. Chicks become familiar with specific odors as a function of early exposure. Differences between the behavior of exposed and naive chicks in the presence of orange odor may reflect neophobic responses by the controls.