Water meter flow needle spinning back & forth

On my inspections I always look at the water meter to see if the flow needle is stopped when all the water is off in the home. Today I saw something new. The flow needle was turning slowly forward then backwards, stopping, then forward then backwards and stopping … it just kept doing that. I looked at the meter next to it just for comparison it was stopped and steady.
Anybody know what this is an indication of ?

Sounds like a back flow issue.

Water heater kicking on and off? (heats the water up, it expands causing back flow, then goes forward as it cools?)

Either it needs one, or the existing repaired.

That sounds feasible Mark but besides the fact that the water heater was turned off I think it was happening too fast to be that. The motion was moving like; Forward one thousand, two thousand, three thousand, four thousand - Backward one thousand, two thousand, three thousand, four thousand - Stop one thousand one, one thousand two, one thousand three, one thousand four, one thousand five - Forward one thousand, two thousand, three thousand, four thousand - Backward one thousand, two thousand, three thousand, four thousand - Stop one thousand one, one thousand two, one thousand three, one thousand four, one thousand five …

Recommend the water company come out and look at it. Also suggest a back flow prevention be repaired or installed. You could easily be causing a cross-link contamination to the neighbors. It could also be that there is someone taking water from a hydrant somewhere if they are tied to the municipal water.