Welcome to WebmasterWorld Guest from 188.8.131.52
Forum Moderators: werty
This being said I really doubt competitors would have a bot for this. Having a bot click on your ad would only increase your CTR, making your ads stay, and if they are artifically increasing impressions with a bot that means their keyword listings would be negatively affected as well (unless their bot was click on their own links only, which would cost them money).
I'd just suggest targetting your keywords better and write more effective/enticing ad copy.