Oh, I thought we were the only ones that had that happen. Only one or 2 at a time, we have a small yard and I usually spot them. With the doggie door they can sneak them out. Last week the little darlings found the new 24" BoBo that I bought for Christmas and somehow dragged it out into the yard before I got home.
Can you wash them and maybe they'll think they have a new batch of toys?