Osmia avosetta, a unique species of solitary bee, builds its nests from flower petals. These bees carefully select colorful petals and carry them in their mandibles to craft delicate, cocoon-like nests in the ground. Once lined with petals, the nests are filled with pollen and nectar for their larvae, then sealed with more petals and mud for protection. Check out these photos!!

Sources: https://www.researchgate.net/.../Female-of-Osmia-avosetta...

https://www.designboom.com/.../special-bee-makes.../