Funny, toy hiding behavior

[capcomop]

I have a three year old toy poodle with a VERY strong prey instinct. He adores small squeeky toys (esp. balls.) and will chase and play with them for hours, even throwing them in the air or rolling them off the couch for himself. He recently has developed a fondness for 'discovering' his toy buried in cloth. He will pick up some cloth (like the sheets on my unmade bed, throws on the couch, or even my skirt if I am sitting with him on the floor) in his mouth and drop it over the ball and then dig for the ball. I cut him some cloth to play with and he LOVES to bury the ball in the cloth, squeke the ball and then dig to get the ball out. It isn't a problem behavior, just different and I was wondering if it was something I taught him without knowing it (letting him find a toy in a shopping bag or playing hide and seek with a blanket) or if it just part of the prey instinct?