You can make a simple ant moat too. I will post complete instructions on another thread, but here are the materials and the end result:
We have nasty ants and earthquakes in California too, and these moats are very sturdy. Fill the moat up to the edge of the jar lid with mineral oil. To clean it out, use a pipette or turkey baster to suck out the old oil through the hole. If it is really dirty, take it out and unscrew the CD and jar from the lid and base, then you can easily wipe it clean and refill.