Wouldn't the spear pit, or otherwise camouflaged stake-in-the-ground, pre-date the razor wire fence as an autonomous knife? Or further still, doesn't the camou

Wouldn't the spear pit, or otherwise camouflaged stake-in-the-ground, pre-date the razor wire fence as an autonomous knife? Or further still, doesn't the camouflaged trap, or non-attendance-required trap of any sort in general, become the original autonomous tool?