Animal experts in Croatia say a bear has learned how to trick people to let him in by knocking at the door. They believe the 35-stone brown bear probably learned the trick while nudging a door to get it to open. Experts speculate the nudging was mistaken by the owners for knocking and that the bear, pleased by the outcome, repeated the tactic. The Loknar family from Gerovo in western Croatia said the bear had knocked at their door three times and they were now refusing to answer the door.