It does sound like they're hunting it, particularly if the areas surrounding yours are dry and sere for the summer. As you back off on watering, they should go elsewhere, although fresh sod should actually be treated fairly well its first summer, so I'd recommend continuing with at least considerable water through July and August.

Check the areas they're in early in the morning or late in the evening when it's quiet to see if there's a nest there. Some wasps are ground-nesting, so you'd definitely want to know that, and I don't know the species of wasps that are native to your area. Checking during the day without a lot of protection could get you stung, so be very careful if you do that.

We have species of bee that nest in the ground (none of which are particularly dangerous and, actually, tend to be the most placid sort of bee that you want around). We also have ground-nesting yellowjackets (AKA wasps around here, although they're not) that you want gone immediately if you find them because those suckers will hunt you down.

If necessary, there are insecticides that can get rid of a ground wasp problem and this is one issue where I have absolutely no compunction against recommending their use. It's them or you. Get rid of them.

San Jose, thanks for the location.

What kind of grass do you have?

What is your watering schedule? How often and for how long are you watering? It sounds like you're over watering, but need more specifics.

Paper wasps hunt for caterpillars like webworms. Those could be in your soil. Mud dauber wasps hunt for spiders but they need moisture and soil to create their nests. If your grass is always moist, they could be harvesting mud. Really need to know your watering practices.

Ground nesting wasps are a problem because every step you take disturbs their nest. Paper wasps and mud daubers are about a docile as any creature can be. Just don't provoke them by waving your arms around or swatting at them. That would be like poking a pit bull with a stick over and over. I used to have a collection of about 300 paper wasps at the house. Here's a close up taken from about 2 inches away (closest my camera would focus).

For perspective, that is 2-inch angle iron holding up the aluminum patio roof on the back porch. I was there for years and never got stung.

"Paper wasps and mud daubers are about a docile as any creature can be. Just don't provoke them by waving your arms around or swatting at them."

Or existing in their general vicinity or looking at them funny or thinking vaguely about walking around them for some species. I've been stung out of the blue by paper wasps merely for approaching within eight feet of a nest I didn't know was there.

While not allergic to any stings and very tolerant of most species, my response to all forms of wasp is, "kill" and I'm also supportive of others with the same reaction.

I've had better luck with mud daubers, but also tend to spot those nests and avoid approaching.

Here's another picture with a story.

That nest is hanging above the back door. The screened door opens out. As the next got bigger in a downward direction, the door interfered with the nest building. I had not realized that when I walked out one day and scraped two wasps off the bottom of the nest. I stopped in the middle of the covered patio and immediately got smacked in the forehead by one of the wasps. It landed on my glasses but launched again in a second or two. When you see the silhouette of a wasp parked on your glasses, there's no mistaking it's a wasp. I looked up and both wasps were hovering in a sort of menacing hover about a foot in front of my face. I stared them down...without waving my arms or swatting, and they flew back to the nest. Total time on the event was, maybe, 5 seconds. I stopped using that door for the rest of the summer and relocated the nest after they were gone in December.

That's a good picture because it shows the cells in the nest which are filled with web worm caterpillars. The trees in my yard were susceptible to web worms, but the wasps kept them out.

those are ground dwelling yellow jackets. once they move in they are extremely aggressive. the whole nest will attack en masse when disturbed. treat the area now before they move in. i remove honey bee hives & capture swarms & 1/3 of the calls i get are for these critters. if they have moved in already call an exterminator. or if you're feeling brave....at night while wearing long pants, a long sleeve shirt, & gloves stick a long necked funnel into the entrance hole & run. after they settle down pour a couple gallons of liquid pesticide or gasoline or diesel fuel down the funnel & run.

FYI. For those reading this thread in the future with a similar issue. Just wanted to let you know it took about 2 weeks of regular watering (scaling back from the first 4wks of heavy watering after laying the sod) for the wasps to leave. Now we are seeing a bunch of moths hatching in the grass... way better than wasps!!

Those are sod webworms and can, potentially, cause damage if they appear in vast numbers. If they're the little moths that flutter up when you mow or walk past, and settle back immediately.

They usually don't and can be safely ignored. I've been safely ignoring my sod webworms for decades now.

Are these sod worms?

I also have wasps all over my lawn and these caterpillar like things crawling around. Live in NYC, tall fescue lawn which is going dormant for underwatering.