Why do some pigs INSIST on drinking by YANKING the bottle, lifting it with their teeth even?

I have a pair in one cage, the boar has managed to unhook the nearly full bottle twice today and flip it into the cage with a large thud. Good thing there's not like newborns to squish! I finally taped it down. I generally tape all the bottles down but after a few days of refilling the tape gets less sticky and/or chewed so i have to re-tape.

I was just watching said boar yanking on the bottle, flipping his head under the bottle, then yanking and drinking again. His older, wiser cagemate was reclining nearby, passively watching him. I could almost hear her warn him: "You're gonna bring the thing down on your head again!"