I adopted 2 piggies over a year ago, ive only heard one of them wheek once and they have never done it again, now whenever they want food or are exited to eat it they just grind their teeth... i looked online and teeth grinding is a sign of unhappiness so now I'm concerned, i built them a huge cage, feed them hay and pellets and veggies 2 or 3 times a day. Does anyone have tips on how to make them happy?