The term for a group of geese is a "gaggle" when they are on land, and "skein" when they are flying. A gaggle typically refers to a group that is not in flight, while a skein describes the V-shaped formation geese create during migration. Geese are social animals and often gather in groups for protection, social interaction, and feeding. The size of these groups can vary, and during breeding season, they may form smaller family units. Different collective nouns for geese exist based on behavior and context, reflecting the diversity of interactions within their species.