Source [link] These cockroaches - that’s right, not pill bugs, these are in fact cockroaches - are one of the most fascinating insects. Cockroaches of the genus Perisphaerus roll up into a ball like pill millipedes or woodlice. They also have “parental care” for their nymphs, providing them with nutrition and protection. When nymphs are born, they are white, blind and have strange tube-like mouthparts, which are unique amongst cockroaches. The mother has four apertures at the bases of her mid- and hind legs into which the mouthparts of the nymphs exactly fit. The nymphs are believed to suck up a nutrient-rich ‘milk’ from these pores. The nymphs cling beneath the mother’s body for the first two instars, and only in the third instar do they develop normal eyes and body pigmentation.
These are affectionately called “armadillo roaches’ in the hobby.