This made it into Space.com? Egads.
Ok, can they explain the aliens preference for, err, "probing" on their visits then? ;)
I've never read a convincing explanation for that.
Some have postulated a genetic oriented thorough assessment of mankind's health.
Some have postulated that it's part of the intimidation process.
Some have asserted that ET's love to eat our brains when we've been scared out of our wits because there's a taste differential in such cases that they dearly enjoy. I haven't put much stock in that one but it could make for some interesting movies--to a point.
Don't recall any other explanations off the top of my head.