We noticed hundreds of small ant like hills popping up all over the yard but they aren't ants. There is a larger hole in the hill similar to the size of a pea and there are no visible insects around the hills. They have popped up fter we mowed and we had an inch of rain in the last three days or so. We dug down around one and found some sort of larvae in the area. Not sure if it's responsible for the hole or not. We live in Oklahoma. Please help us identify what is making these hills! Thank you