In my previous career I worked in IT for a bank. There was someone who would steal things from my lunch box. I also used to raise Yorkies. One night (i Worked 3rd shift) I took some of the dog's KIBBLE AND BITS and sealed it in a plastic bag and left it next to my lunch bag. Well the thief must have thought someone forgot it because when I came back from lunch, my coworker of many years was sitting in front of the computer screen chowing down on the dog food like it was a good trail mix. I watched him eat the whole bag and told him at the end of the shift it was dog food. I never had a problem again.