DENVER (AP) -- Animals on the airfield are causing problems at Denver International Airport, where they can be struck by planes and cause millions of dollars in damage.

Rabbits at the airport are attracting raptors and coyotes that have collided with aircraft, causing damage to windshields and wings. In some cases, animals also can get sucked into jet engines. At least five coyotes were struck by planes at the airport last year.

Animal strikes caused more than $4 million in damage to commercial aircraft at DIA in 2005.

"As fast as those airplanes are going, even if you have a medium-sized bird, that's a pretty big force that can cause damage," said Mike Yeary, U.S. Department of Agriculture Wildlife Services director for Colorado.

Bird strikes with aircraft are estimated to cost civil aviation more than $300 million a year nationally. More than 6,300 bird strikes were reported for U.S. civil aircraft in 2004, according to Bird Strike Committee USA.

"If a large aircraft were to hit a large hawk or an owl, especially during a takeoff or landing, that could possibly cause -- at minimum, damage -- and in the worst possible scenario, a crash," Yeary said. "When you get flocks of them they could possibly clog up the jet engines."

The airport contracts with Wildlife Services to try to keep wildlife away. Tactics include shooting off a type of fireworks that frightens birds away or killing rabbits where they are deemed an immediate safety hazard.

DIA also has used a private contractor to relocate rabbits, which sometimes nibble on engine wires of parked cars.