From what i have observed, a duck-flock holds much more together than a chicken flock - but i have not much experience with chickens… And you will become a part of the flock too, a very respected member, having control over food, water and treats!
All that chatter and squeaking going on in a duck flock makes sure that everybody is accounted for and they all get the latest news. One duck finds some good eating, the whole flock is alerted and moves in…
Those vibrations are a sign of excitement, many of my ducks vibrate when they see my hand reaching out for the cat-food and before they grab it out of my hand.
Ducks also understand that vibration with the right frequency makes mud softer and allows them to drill holes. Some of my drakes also "tap-dance" on the mud to soften it up for the girls, it looks hilarious!
Some other examples of duck behavior fro my flock:
I picked up our first six ducklings at the local farm store and they immediately huddled together in the far away corner of the box i was transporting them in, always looking at this huge "thing" that was taking them with it. The moment we left the store all six looked up to the sky in awe - they obviously had never seen the sky before - fell on their backs and forgot to get up again, were just watching at that big blue thing over their heads. Still as grown up's the runners sometimes stand still in the grass, just watching the big blue sky, day-dreaming.
In December 2018
i fell through a rotten floor outside and broke my left ankle. The ducks were outside, foraging and heart the crack and the thud of the impact and came running to their duck-platform curiously looking what had happened. When they saw me lying on the ground they all started quacking/rasping in panic, watching me crawling up the hill and along the fence back to the house. Whenever i stopped crawling and rested their quacking became louder as if to encourage me not to give up…
Since then, the duckies always have an eye on me when i'm working outside: There's always at least one duck observing what i do - i mean, there is always a chance that i have to dig a hole or a trench, exposing some underground critters…
Ducks don't fight much within the flock, chickens definitely behave more aggressive with each other and to any thread from the outside they stand together, drakes in the first line. There was an opossum around the house a couple of days ago in the evening and all ducks stood very close together, forming a large, noisy, intimidating mass of bodies. The drakes plushed up their feathers to make them look twice their size. They literally herded that poor, confused 'possum out of the open gate and were watching carefully as it strolled into the brush.
Ducks do grieve and miss a lost flock member: For days after Donald, my larger drake
disappeared without a trace in the spring of 2018, Curiosity and Nona duck were running around, searching for him, refusing to eat. And i will never forget the
sad view in the face of little Mini Duck after i had to bury her little brother recently. Fortunately they get over it!
A new development in my flock from this year: Either Limpy, Katharina or Curiosity Duck (my Indian Runners) make sure at bed-time that nobody is left behind by refusing to go inside if anybody is still outside. On evening Limpy was forgotten in the duck-pool and i closed the door of the duck-house for the night, was just about to go to bed when i heard him rasping outside and running around alone. I don't know if he was actually hiding or just fell asleep and i didn't saw him (the pool is up the hill and if he sits right behind the rim he isn't visible). But since then the ducks too pay more attention at bedtime, making sure everybody is inside.
Last summer, when Katharina Duck had her ducklings, i was first very concerned the other's would attack the ducklings, but no: Apart from the occasional butt-kick during treats-stampede they all cared and looked after the little ones and they became an important part of the flock.
Integrating new ducks to a flock is much easier than with chickens: One to two weeks of "see but no touch" separation and you can let the newbies loose. There will be some rubbing, but not as brutal and bloody as with other fowl.
If the rate of duck to drake is ok (3 ducks per drake, at least) you can have multiple drakes in your flock, i'm not sure if you could have multiple roosters. (?) - I guess those would divide the flock between them, whereas my drakes peacefully sit right next to each other.
Ducks can learn tricks: Two of the White Layers, Bazilla and Earthquack literally laugh when i approach them, making an eating movement with my hand, saying "Num! Num! Yummy duck!" - they open their bills wide without quacking pull their heads down and squeak, pretending to flee from me only to turn around and then quacker at me. - And sometimes vibrate…
Long answer, hmm? If you observe your duckies and bond with them, you will also find out that no duck is like another, they all have different personalities, preferences and behaviours.