$50 is a LOT to pay for a very small piece of plastic BUT it would be worth it if the gadget lived up to the hype. It's certainly amusing screeching ‘exterminate’ whenever it hits an obstacle. Unfortunately – contrary to the claims – it does not cope well with table edges (we tried a couple) and falls off easily. Had a mind to return it but I put so much effort unto unpacking (unfeasibly fiddly) and putting batteries in I couldn't be bothered.