AKA adult pubic lice or crabs, saber-toothed crotch crickets are parasites. These insects are generally found in the crotchal area and they may cause itching.
Little Billy gave the town hooker $25 and all he had to show for it were some saber-toothed crotch crickets.
The only logical explanation for the instant and sudden need to scratch your balls that you can explain to women.
"I couldn't help it, honey! I had to scratch! It was the Saber-Toothed Crotch Crickets! You know, tiny little buggers with these giant teeth that just randomly sink their teeth into my sack! Hafta itch that!"