I don't know if we've done this, but:

Unexplained sheep attacks 'caused by aliens in UFOs', farmers claim

"Farmers near Shrewsbury claim to have witnessed sheep being “lasered” by unidentified light from UFOs. They have found sheep with “neat holes” while their brains and other internal organs were removed. Other animals have lost eyes or had their flesh “carefully stripped away”, usually on the left side."

Is this incontrovertable proof of the existence of aliens?