There are a few things that attract them loud noises seem to be a big attention getter for the horde so no air horns car alarms WILL attract them any loud noise that can be heard for at least to miles brings them in faster than you can start to pick them off. Yelling only attracts those that are in the immediate area so feel free to yell when they swarm from the car alarm now don't take it the wrong way you won't have an army of them on your door step just a handful just enough to waste a clip on so beware of loud noises remember silence is your frend usually.....