their pen is right by the water and since June every night they would go right In at dusk to eat dinner and be put up for the night and every morning at dawn we'd let them out. For some reason this past week they have refused to leave to lake to go in their pen. We've tried coaxing them with all their favorite treats and no luck!! Nothing has changed besides the fact that one duck is injured and has a slight limp. After treating the problem we left her down with the rest of the ducks so she could get off her feet and swim all day. For three days after they all went in no problem like usual but then Sunday they refused and nothing we have tried has worked!!! Any suggestions?