how do things go missing?

I haven't been able to find my TS grey Baxters for ages,they are not in the usual places-bags/laundry basket etc,infact I cant find them since I went away a couple of months ago but I didnt take them with me,so I dont think I have left them there.I had gone off them for awhile,but now they seem ok again to wear with chunky knits and boots.I wonder if the catsitter nicked them?