How Do Carpenter Bees Make Perfect Holes?

Q: How do carpenter bees make a perfect half-inch circlular hole without a compass, ruler or drill-bit?

A: Carpenter bees are remarkable non-tool-using insects! They use their mandibles to grab and pull up small splinters, which are discarded behind them as they penetrate a wood surface. The holes are not perfectly round but they appear so to the naked eye. After the female bee has tunneled for approximately one inch, she changes direction to bore at a right angle to the original entranceway. As she progresses down a plank, she makes chambers on either side of the main tunnel.Each chamber receives an egg and a ball of pollen to feed the larva when it hatches. Each chamber is sealed with particles of wood. Bees may use the same tunnel for several years. The best way to stop them is to squirt insecticide in the hole and seal it with caulk.