Mystery Door Blob Turns Out to Be a Helpful Backyard Visitor.

Many Benbrook residents have recently spotted a strange, quarter-sized blob attached to their front door and jokingly wondered if it might be an alien visitor.

Neighbors quickly cleared up the mystery with a more down-to-earth answer: it was a praying mantis egg sac, known as an ootheca.

An ootheca looks like a small, foamy, tan or light-brown lump that hardens into a protective shell. It often appears on doors, fences, branches, or outdoor furniture during the cooler months. Inside are dozens, sometimes hundreds, of tiny mantis nymphs waiting for warmer weather.

For homeowners, it is actually good news. Once the eggs hatch, the baby mantises spread out and become natural pest control, feeding on mosquitoes, gnats, flies, and other insects.

While it may look unusual at first glance, the ootheca is harmless and a sign that spring will bring a fresh batch of beneficial garden helpers.