Most thieves are actually really bad at what they do

Quite interesting.
Generally the US offenders are mostly teenage boys going through a phase. They're not more likely to have come from a poor home. And this kind of crime just does not pay anyway - they are doing it for the thrill.
This all sounds very plausible for the UK too.

So putting bear traps down would just make it more exciting for them.
Better to warn that all trespassers will be locked in the bathroom until they have had a good wash and combed their hair.