Lung infections due to water-logging effects would likely be common, as well as mold, and fungi would be rampant (yaaay, food source!).
Fishing would doubtless be a very important part of the humanoid food chain. Birds of prey, especially those that feed on fish, would have their greatest asset - their vision - nearly gone.
Other birds, like woodpeckers, nut, and fruit eaters, would probably not to too badly, as they would live primarily in the upper canopies.
In the lower regions, bats might reign supreme, as far as fliers go - probably only to get caught in massive spider webs, or some other stalking predator.
Of course, there are many bats with great eye-sight that would probably hand out in the under-canopy. Being nocturnal, some species might become carnivores beyond the average insectivore, hunting out sleeping birds. They would likely be much more adept at climbing and crawling than bats today.
Ants, or a similar cleanup creature, would definitely be common on the floor.
The bottom regions of airspace would likely be inhabited by all sorts of fliers, who would try their damnedest to avoid the floor, because of the voracious hoards there.