Native tribes used to catch monkeys by hollowing out a coconut and filling it with rice or other delicacies, then leaving it tethered to a tree for a monkey to find. A monkey would reach in and grab the desired delicacy and be trapped because the hole had been deliberately made just big enough for a flexible hand to enter but not for a closed fist to leave. In short order, the monkey went from getting his dinner to being someone else’s dinner.