These swallows learned how to fly in and out a parking garage—where they made their nests—by triggering the detectors on the automatic doors. Watching them flying in and out is simply amazing.
I imagine the swallows probably liked the garage's environmental conditions, safe from the elements and with a more stable temperature, and somehow quickly learned that approaching the doors opened them automatically.
DISCUSSION
I heard about some Ravens on a northern work site here in Canada that would sit in front of the motion detecting work lamps to keep warm. Whenever the light went out, they flew up and moved around in front of the sensor to turn them back on.