A Penn State researcher found that male groundhogs emerge from hibernation before female groundhogs so they can pay the females a visit.

Stam Zervanos, associate professor of biology at Penn State Berks, observed a male waiting outside a female's burrow. The female came out of her burrow and the male remained with her for two days before traveling to another female's burrow. Then all three groundhogs stayed alone in their burrow before mating.

Groundhogs tend to end hibernation in early March, which is when mating occurs.

These visits happen in February, and no mating takes place during this time.