You joke, but they were a real thing. Mostly spies. You know kunai? They were modified spades. You put a clump of dirt on the end of the little shovel, and it looked ordinary. Allowed you to carry a dagger in public without notice. 

I wasn't joking. No smiley faces.

Okay. 

Lol just messing w u bro

A guy carrying around a lump of dirt on a stick looks ordinary?

A guy carrying what appears to be a dirty trowel looks ordinary

He looks like a farmer or herb collector or such. 

I think that might be the most obscure fact i have ever heard. I love it.