I want to believe... But Occam's razors makes me think it's birds, meteorological phenomena, and other things you can misconstrue for more in a high stress situation (or through IR cameras).
I think this problem is difficult for science to study because it's not readily reproducible. Not only that, but any evidence that /does/ exist has been ridiculed, suppressed, and/or outright ignored for too long. Now we're seeing efforts to reduce the stigma, and I applaud that.