If you don't know the genders, you might be happy to have five. I had a pair of pekin ducklings once that I picked up when I was left with one lone drake, hoping against hope that both were girls or both were boys. No dice. I had an even pair and that poor girl was so sexually harassed until I picked up some more females. The last thing you want is more males than females, ugh. If you had kept three, you might have ended up with my problem. Plus, who can resist cute little ducklings? And five are as easy to care for as three
Don't mind me, I have morefowl disease and I try to spread it to everyone.