Some species are so needy. The large blue butterfly of Europe has an impostor life cycle that depends on receiving help from an entire team of other animals.
The caterpillars impersonate the grubs of a particular red ant species, going so far as to secrete the same chemicals and make the same noises. The duped ants care for the impostor caterpillars even as they devour ant grubs. After 10 months of freeloading, the caterpillars become butterflies and take off on their own.
The ants, however, are picky about neighborhoods: they only live in soil that's warmed by the sun. When Britain's rabbits died of myxomatosis in the 1950s and farmers simultaneously stopped grazing cattle, the grass got longer, the ground got cooler, the ants left, and the butterflies became endangered.
Now that conservationists understand the insect's life cycle, they've reintroduced it along with the ants and cows to graze the site. They reported this year that the blue butterfly population reached 20,000.