Are gnats one particular insect or does it refer to any number of tiny insects that tend to swarm around our faces and counters? One place I work has tiny fruit fly’s that swarm around the recycle bins. Everyone calls them gnats.
One at a time is the usual MO.
Unless you are bike riding and hit a freaking cloud of gnats. If you are slathered up in sunscreen they will stick to your skin and die by the tens of dozens. You literally look like someone attacked you with a pepper mill. Of course you get them in the teeth also.