Flock, paddling, raft, team or brace of ducks.
* A brace is two ducks. Also a safe of ducks (on land)
A badelynge is an archaic term for a group of ducks on the ground.
A group of ducks on water is called a raft while a group of ducks flying is called a skein or a team.
A paddling of ducks, a raft of ducks, a team of ducks, a dopping of ducks
Ducks in flight are a flock. Ducks on the ground are a badling. Ducks in the water are a raft, team or paddling
Ducks
A single baby duck is called a duckling, now make that plural. A group of ducks, however, is called a balding.
ducks and gaggle
A group of ducks is called a flock.
This link will give you many including raft and flock. http://www.ask.com/pets-animals/group-ducks-called-b01f5dc2e39a782b
Ponyboy is a chick in a group of ducks
I do not know about a "crate" of ducks, but a group of many ducks is called a gather I think. Check out a few more answers too.
They group together