Keith has a biscuit obsession and I kept on finding nibbled biscuits all over the place. We found out that actually he'd learnt how to open the tin with his feet and nose... he mostly nibbles the edge and then "hides" the rest of the biscuit, rather than pig out on it. I then find the biscuit (he always puts them under the telly or the wiifit) and chuck the rest away. Doesn't seem to have done him any problems!