Ducks

I have had two ducks for about a year, and they were both really young. One is brown(cookie) and the other was yellow(Cream). A couple of days ago Cream died because she was attacked by something, and Cookie has been really depressed lately. He won't eat, and we had to bring him inside the house so he doesn't get lonely, but you can still tell he's upset. He won't eat much, and I don't know how to get him to eat. He's probably so confused since his best friend is dead, or maybe he doesn't even know Cream is dead and thinks Cream is just gone? He is still devastated either way and I can only provide him comfort with my company