Before the skin is lost it loosens, making the animal appear whitish over half of the body. The rear half is lost first, the skin splits and they pull themselves free with the front limbs. A few days later the process is repeated with the head end. The cast is often eaten, probably to replace the calcium carbonate. Woodlice are very vulnerable during moulting and are often attacked and eaten by other woodlice, particularly in cultures.
Reproductive behaviour is difficult to observe as it usually takes place when it is totally dark.
The woodlouse does not have any lengthy courtship. When the male woodlouse finds a receptive female he stops, waves his antennae at her, eventually resting them on the female. If she hasn't left by this stage he then crawls on to her back. He spends a few minutes licking her head and tapping on her back with his front legs. Trichoniscus pusillus are definitely known to do this, my own experiments have also shown that Pocellio scaber and Oniscus asellus are also able to produce offspring when they have not mated with a male.