They could be bees or wasps, the ones I had were yellow jackets which are a wasp....I have had several of the ground nests and they are horribly aggressive, they will actually chase you all the way into the house.
First couple times I used a mix of gas and oil applied at dawn and ignited. The last one I had was under a wooden deck next to the house.
I found a treatment using lots of dish soap and about 3-4 gallons of very, very hot water.
Again, poured in to the hole at dawn as it's the coolest time of day to protect myself from being stung and because they're mostly in the nest at that time.
Saw a few stragglers thru the day and by the following morning a skunk (I think) had come and dug up the rest of the nest for the larvae.