Need advice. 6 ducks

[casonchaos]

I have 6 ducks and 3 chickens (almost positive one is a rooster)
2 ducks are pekins. About 2 months old.
2 I'm almost positive are khaki Campbell's, are about 1 month old. And 2 brand new ducklings.maybe a week old. I'm thinking Rouen or Black Swedish.

My pekins have gotten big, fast.
My khakis are fair sized.
And the ducklings are SMALL.

The bigger ducks are mean and seem to aggressively peck at the small ducklings also it seems like they are trying to squish them.

I am a first time bird owner and any advice is welcome.
I'm looking for ways to introduce my older ducks to the babies without them hurting them...

 

[KingOfTheCoop02]

Adult birds can't be kept with baby birds.

 

[gallos el bravo]

Not good small ducks/chicks with big ones they can confuse them as small prey or something and end up hurting them or end up kill them