Damned Burglars

[mukapahnpy]

A would be burglar just attempted to rob my house. He crawled through the basement windows and crawled back out. Everyone is ok, nothing was stolen or damaged (as far as I know, I received the phone call at work). My kids are now dramatized, I'm dramatized. Too man scenarios are running through my head; good and bad. Time to implement better security measures. What is the best deterent for basement level windows?