We just got our ducklings Friday. 3 welsh harlequin hatchlings. After doing what research I could find on making things safe, I decided to introduce them to our 2yr old Border Collie/Husky mix. He can be pretty high strung at times and a bit hard headed, but he's really smart. The goal was for him to get a smell, but not touch and then just lay and watch. He's been known to hunt small animals in the yard and tried to chase wild ducks when we were out for walks. (I didn't let him.) I have never seen him try so hard to please me and do exactly what I wanted as he did during that meeting. It was a complete success and he really wanted to go back in the room a little while later, but he settled down very well when I called him away. I'll still closely supervise him around them, but hopefully he'll get the point that these ones are not his playmates or toys. As regards the cat who's a 20 lb Maine Coon, I don't know if I should do any introduction or not? Any ideas? If I wait till they're grown they may be scared of each other, but the ducks will be living outside when they're big enough and the cat is indoor only. Also, does anyone have experience with ducks and guinea pigs? I'm wondering if we could build a relationship there so that we don't have to move the guinea pig pen out every time we take him outside, but could put him in the enclosure with the ducks maybe? Thanks for your input!