This lovely wasp can be found drinking nectar at flowers throughout the eastern United States right now. It is a good wasp to have around the garden because the females round up leaf-rolling caterpillars — the kinds that eat your plants — to provision their nests.
When it is time to reproduce, the female wasp builds a small nest, often in a wood bore made previously be a carpenter bee. She paralyzes caterpillars with a sting and flies them to the nest, stuffs one or a few into the deep end of the hole, and lays an egg there.
Then she seals up that cell with mud and repeats the process, but famously leaves empty cells between occupied ones, possibly to fool invaders into thinking the nest is empty.
The eggs hatch into wasp larvae that feed on the caterpillars.
August is a great month to look for interesting wasps and bees. All you need is a sunny day, flowers, patience, and luck. If you take a camera you might capture a great moment.