A Series of Tubes

Figs and fig wasps have a tightly coordinated reproductive cycle, and have been cospeciating for 70 to 90 million years. The pollination of figs is accomplished in an internal cavity only accessible to a specific species of wasp. The wasp enters through an opening that is only just large enough for it to get through, loosing it's wings and antenna in the process. Pollen on the wasp pollinate the fig's internal flowers, and the wasp lays it's eggs in some of the flowers before dying there. When the male wasps hatch, they fertilize the unhatched females, and burrow tunnels out of the fig before also dying inside it. When the females hatch, they exit the fig through the tunnels, taking pollen with them to search for a fig within which to lay their eggs.

https://en.wikipedia.org/wiki/Syconium https://en.wikipedia.org/wiki/Fig_wasp