[Drawingwords]

That's pretty interesting. The pigs are adorable too! I trained one of mine to come out of the cage when the door was open for floor time and he would go back in when he needed a wee or water. The girls I have now have been audio trained with a bell for food. When they want food or if I don't give it to them fast enough, they ring the bell.

The object permanence is a sicentific, if not behavioral observation. By nature they are foragers and are accustomed to digging for their food. The lettuce and towel was just incorporated into their already natural ability. That was very interesting and I think it's neat you are working with your animals this way. This was, how seeing eye dogs were first found. Because people did experiments that didn't hurt the animals at all but tested their strengths and now millions of people are living normal lives because of them.