I might be getting several free ducks tomorrow. The lady who has them says they are 4-7 years old. I have not had ducks before, so I'm wondering if that's really old for them? Would it be likely they still are laying at that age, or are they like chickens where after a couple of years they don't lay so well anymore? I'll likely take them no matter what, just wondering whether ducks that old will be useful to keep around (for eggs/raising more ducks to eat) or if they'll be going straight in the freezer.