There are a few telltale signs that wasps may have nested in your walls. If you hear a high-pitched buzzing sound coming from your walls, this is a good indicator that wasps are present. You may also see wasps flying in and out of cracks or holes in your walls. Another sign of a wasp nest in your walls is if you see wasp larvae or pupae. If you suspect wasps have nested in your walls, it’s best to call a pest control professional to safely remove the nest.