What is a group of Moorhens called?

A group of moorhens is commonly called a Waddle.

A collective noun is a noun that describes a group of individuals or objects. For moorhens, the collective noun used to describe them is a "fleet." When moorhens gather together, they form a fleet, which is often observed in marshy areas, lakes, or ponds where they reside. The fleet of moorhens can be captivating to watch as they navigate the water bodies, pint-sized yet swift, with their dark plumage and distinctive red bills and frontal shield. They move together as a cohesive unit, exhibiting a synchronized motion and displaying their social behavior, such as foraging, feeding, or interacting with each other. In the presence of danger or external threats, the fleet of moorhens may signal each other with specific calls or take-off together with their characteristic running-on-water motion. These collective actions by the fleet demonstrate their strong sense of community and unity among the moorhen species.