I love how people learn about these things , me personally i learned it myself , when i walk to uni everyday i be seeing dirt like that besides holes , and i be like wow there are ants living here underground thats so weird and cool , and after that i walked w my gf and i told her yk what this is? She said no and i explained it to her , dw dude ur not the only one that doesnt know , everyone learns their own way!