Water Heater Ant Colony

A colony of ants has chosen the top of my water heater to settle their colony. I see them walking on top of the water heater all the time, going in and out of the holes they've chewed through the metal lid. I'm not quite sure how deep the colony goes, or how a water heater's inner structure is good for making a colony.

There is one major detrimental factor to locating an ant colony in a water heater...it's a water heater. Every time the water heater turns on to refill up its tank, the colony pours out of the water heater running for their lives in fear. Not sure if it's the heat or if their homes are getting filled with water. They carry their precious larva in their teeth, and hide wherever they can for a couple of hours. Then they return. This happens every time the water heater turns on. I'm wondering how long it will be until they decide to abandon this foolish idea. How can one have a successful ant colony if several times a day you have to abandon it?!?