HELP! I've had my ducklings for about a week now....I went and watered adn fed them less than an hour ago and they were fine. I heard one of them chirping and went to investigate....found one dead. In the next 15 minutes two more died...they were panting and just basically went to sleep. I took two more groggy ones and put them in the bathtub with some cooler water adn have been holding them and chatting them up. One still seems kinda groggy...but awake... what's going on? any advice?