I cant even tell you how many ticks we found in my dog after a walk this summer. So many we didn't even want to take our dog hiking (which is a hobby for us.) We aren't due for a new collar until january and Im finding fleas. Ive made sure her collar is tight enough. It hasn't been wet, but twice and very briefly (approximately 1-2 mins.) This is our 2nd or 3rd collar and this is the first one thats been horrible, but Im leary to even try it again!