This is one of the strangest things I've seen.
A colony of ants living in the gas cap. We've seen ants on the boat but when we loosened the gas cap they were everywhere. You can see the eggs that came out when we tapped it.
This picture was taken after wiping most of them off.
Hopefully they weren't able to enter the fuel tank, that would probably create issues. Today a spider rode shotgun with us out into the lake and then unbeknownst to him, became fish food.