Can a flying creature with Hover be knocked prone?

Question

If a creature is flying and has the Hover keyword, what happens to it when an attack power inflicts the prone condition on it?

(created to discuss the issue as raised in Would flying monsters ever land during combat? and What can a player do to force down a flying creature?)

Answer 1

It falls to the ground as normal

The Hover keyword does not affect falling prone. As per the compendium entry for Hover:

Hover: If a creature can hover, it can remain in the air if it is stunned.

Note that the compendium entry for Stunned specifically confirms this:

Stunned: The creature falls if it is flying, unless it can hover.

Otherwise, it follows all the rules as normal for Flying:

Falling Prone: If a creature is knocked prone while it is flying, it falls. This means a flying creature falls when it becomes unconscious or is subject to any other effect that knocks it prone. The creature isn’t actually prone until it lands and takes falling damage.

Note that the Stunned condition does not inherently cause a creature to be knocked prone, thus the special rule for flying creatures falling under the definition of Stunned, and the special counter to that rule in Hover.