Human architects could learn a thing or two from the unique bee species, Osmia avosetta.
With a flair for the colorful, O. avosetta makes a "petal sandwich" out of two layers flower petals inside a small burrow it digs in the ground, cementing them together with clay or mud. Then it caps the chamber with a mud plug, which seals the humidity inside while letting the outside harden. It's the perfect environment for the egg, said Jerome Rozen, curator in the Division of Invertebrate Zoology at the American Museum of Natural History.
"They've found a way of protecting this immature stage by creating an environment with fairly high humidity," Rozen said. "The humidity is high because the chamber is constructed with two layers of petals with mud in between, which means the food will not dry out when the larvae feeds. Meanwhile the outside becomes very hard like a nut. This makes it very comfortable and very safe because nothing's going to come down and crush them. Anything that wants to eat them from above is going to have a hard time."