Water Food stuck in nozzle

Earlier today I noticed the water level in my pigs' water bottle hadn't dropped. I inspected it and found the ball was stuck up in the nozzle. I cleaned it out and a huge wad of chewed up food came out! I put it back together and fed the boys; later today I investigated it because Little Bear would try to drink for a second and walk away...and it was clogged again! I know who my culprit is (Gimbly), because he is constantly going back and forth when I feed them pellets. Is there anyway to prevent this? I'm concerned that the bottle will get clogged on one of my longer work days. I have no idea how long it was clogged this time. They have a big water bottle so I only have to change/refill it every couple days. They don't get pellets very often, maybe every other day, so I'll have to be careful with the time I feed them.