[neurotech1]

Actually, Relatively small birds have been known to penetrate the windshield of a Cessna and injure the pilot or even wreck the engine of a single engine of a jet like a BAE Hawk.

See video of a Canadian CT-155 Hawk (Not F-16 as titled) https://www.youtube.com/watch?v=zN_Zl64OQEw

For an airliner like an Airbus A320, a small bird can damage the engine fan blades and require an expensive repair. If the bird goes through the core even minor damage becomes very expensive to fix.