I often get asked if those flashing light devices being sold on-line and at many hardware stores have any effect on pack rats. The lights are almost $50 each.
I have tested these devices with a pack rat in a terrarium and rigged the flashing light where I could turn it on and off remotely. I observed no change in the rat behavior with the light on or off.
But was this fair? A captive rat has no where to run and can't get away. So I ran another test with a wild rat in an outside nest. Do they work? Watch and you decide.
