These tunnels act as shelter during the day, offering the larva a good camouflage, from which they will emerge at night in order to feed. Larvae will pass through approximately five instars, although under adverse conditions there may be as many as 40 moults. Pupation occurs within the tunnel and shortly after eclosion, the adult form emerges. Adults are unable to feed, due to atrophied mouthparts. Development of eggs may take from 6 to 38 days, larvae from 60 to 200 days and puparia 10 to 50 days.
Antennae are long and thin.
Adults reach between 4 and 7mm in length with a wingspan of 12 - 17mm. Often perceived as purely a household pest, the clothes moth has been responsible for losses of industrial revenue exceeding 12m in 1 year, although this has become less severe with a move away from natural fibres to synthetic fabrics. Other species have however filled this vacancy, most notably fur and carpet beetles. T. bisselliella has also been noted to have infested dried vegetable material.