It happens. I have gone through way to many of these darn $20-40 bulbs.

Have a 5"x5" circle burnt in the carpet from the cat knocking a light over from one of our tanks about a year ago. Thought it was cute that she would cuddle the light for warmth up until that point.

now we always have the lights secured, and try to keep her away.

damn cat. *grumble grumble grumble*