Live Science has an article that discusses the heartiness of roaches.  Three quarters of all plant and animal species went extinct after the meteor struck Chicxulub at the end of the Cretaceous Period, how is that roaches made it through the extinction that followed?

When the rock now known as the Chicxulub impactor plummeted from outer space and slammed into the Earth 66 million years ago, cockroaches were there. The impact caused a massive earthquake, and scientists think it also triggered volcanic eruptions thousands of miles from the impact site. Three-quarters of plants and animals on Earth died, including all dinosaurs, except for some species that were ancestors of today’s birds.

How could roaches a couple of inches long survive when so many powerful animals went extinct? It turns out that they were nicely equipped to live through a meteoric catastrophe.

If you’ve ever seen a cockroach, you’ve probably noticed that their bodies are very flat. This is not an accident. Flatter insects can squeeze themselves into tighter places. This enables them to hide practically anywhere – and it may have helped them survive the Chicxulub impact.