water spray

hi all
I wonder if anyone can help?
I am trying to make an automatic water sprinkler connected to the mains water and triggered by a movement sensor. I have the sensor but cannot think what to use in order to make an electric tap (so the sensor can switch it). The reason for doing this is I get alot of foul in my garden from rodents etc, and I want the sprinker to be set of by the movement of the pest. I was thinking of useing bonnet (windsreen) washer jets from a car for the sprinkler itself.
Any ideas greately recieved
Cheers
Phil

Well, there are several soloniod valve choices for in-ground sprinkler systems. Ususally 24 volts (don't think you want to mix mains + water, even targeting rodents). A 3/4 inch size is about the same as a garden hose (threaded ends fit). Rainbird is one company, but there lost of others.