Hamish and Misty used to be outdoor cats and they were forever loosing thier collars??
We started to think someone was strealing them
but then thought they must be getting them stuck on bushes and pulling in opposite direction to get them off (they were never on that tight)
Just enough so's you could pull them over thier heads, I have now seen the Horrors of what collars worn the wrong way can do
and in future, If the area is right, and deemed suitable for letting Furbabes out, I would now have them chipped instead
never did find out where the collars went to, but between 5 Furbabes, we lost count of how many collars we had to replace