An apparatus for observing behavior of pouch-young opossums

Opossum fetuses undergo most of their neurological development within the mother's pouch. This extrauterine growth offers unique opportunities not shared by placenta mammals for early behavior studies. Described here are an apparatus and technique for observing the behavior of pouch young. The apparatus restrains the mother and retracts the pouch flaps within an environmentally controlled setting similar to that inside the mother's pouch, allowing the opossum young to be observed in an almost natural state. The investigator has ready access to the young pouch through side windows that have slotted curtains to prevent sudden changes in the chamber environment. Because this apparatus provides a simple noninvasive approach, fetal behavior can be observed long-term, encompassing the entire sequence of behavior development within a chosen time-interval.