What attacked my duckling? Don’t open if your squeamish

[Howard E]

If this was a weasel or stoat, there would probably be many more deadn's that one or two. Like a whole bunch at one time, with only bites to the back of the neck to indicate what got em.

Rats are moving to the top of the list. So to the OP, what made you think rats in the first place? Do you have them around? Tunnels? Other evidence? How many and how close? Is the housing for these birds "rat proof"?

 

[Howard E]

BTW, can you provide a photo of this housing?

 

[MillersFarm]

Do you have any hawks around your area? From what I see in the picture it looks like a hawk attack, They'll strip the meat clean off the duck straight to the bone like that. But from your description it sounds like it could of been a weasel that got to them..

 

[Hybridchucks]

Weasel or rat I reckon