Adding new ducks into pond?

In our backyard there are about 6 ducks in this huge pond. They were all there when we moved in. If I add my 2 ducklings, will they attack them? I put them in at night but during the day they go free.
Answers

BlkBear

Common sense says, put them out SUPERVISED ONLY, at least until you know they are going to be OK with the older ducks.