Chimps with spears...
Story here.
Note that it's the women escalating the weaponry.
Don't know if anyone spotted a mysterious black slab in the vicinity...
Seriously, the operation (poking a stick into a hole to see if you can extract a small mammal) seems to me to be more of an extension of tool use than a weapon. Essentially an extrapolation of the stick into the termite mound. No real threat involved, just a way to get something to eat out of a hole.
Now, let me know if a chimp ever kills another chimp with one of these "spears."