December 5, 2008: An Air Force base in northern Australia is overrun by wallabies. These critters, that look like miniature kangaroos (whom they are related to), weigh ten to twenty pounds. But if struck by Australian F-18 fighters on takeoff, or landing, damage, or disaster, can ensue. There have been two recent collisions. One F-18 was taken out of service for a short time so repairs could be made, the other aircraft suffered no significant damage.

The wallaby infestation is particularly dangerous at night, when herds (dozens) of wallabies wander onto the airstrip. So far, fences and efforts to shoo the critters away have not solved the problem. A new "wallaby management plan" is in the works, which will employ a wide range of methods, including killing the little beasts, in an attempt to make night time flight operations less risky for the aircraft (and surviving wallabies.)

Bird strikes are actually  more widespread problem. There are about 5,000 incidents a year. These often just mean replacing windows or canopies, or wherever the bird hit. But from time-to-time the damage is severe, and some aircraft have been lost. Naturally, critters that can't fly are, technically, easier to control. But not always, as in the case of the wallabies.