Bacteria live inside bacteria in mealybug
The ability of life forms to co-opt each other has taken a novel twist: Scientists have provided the first proof that a bacterium takes up long-term residence inside another bacterium. Both the host and the tenant, in turn, dwell inside a mealybug, which passes the bacteria on through its own eggs.
Many types of insects, including mealybugs and aphids, play host to bacteria. In return, the bacteria often provide nutrients to the insect.