Two wardrobes in the same house can have completely different moth problems. The difference is not luck but a combination of fibre type, residue and how often the space is disturbed.
The larvae eat protein, not cloth
Adult clothes moths do not feed at all. The damage is done by larvae, which digest keratin, the structural protein in wool, cashmere, silk, feathers and fur.
Cotton, linen and synthetics are not food. They are chewed through occasionally when they are in the way, but a wardrobe of cotton shirts is not a target.
Which explains why the holes cluster in exactly the same few garments year after year while everything hanging beside them is untouched.
Residue makes a garment more attractive
Clean wool is edible but not especially appealing. Wool carrying sweat salts, skin cells, food traces or hair oils is markedly more attractive to a female looking for somewhere to lay.
This is why damage concentrates at underarms, cuffs and collars rather than spreading evenly across a jumper. The larvae feed where the residue is heaviest.
It also explains the standard advice to store knitwear only after cleaning. The point is not hygiene but removing the signal that draws the adults in.
Darkness and stillness matter
Clothes moths avoid light and airflow. They favour the back of a deep wardrobe, the underside of a folded stack, a lidded box under a bed or the fringe of a rug beneath furniture.
A jumper worn every fortnight is handled, shaken and exposed to light often enough that a population never establishes on it.
The garment that suffers is the one packed away in spring and not looked at until autumn, which is exactly the wool that most deserves protecting.
Why cedar and lavender underperform
Cedar oil and lavender are repellent at high concentration in a sealed space. In an open wardrobe the volatile compounds disperse quickly and a cedar block loses most of its effect within months.
Neither kills larvae already inside a garment. Adding a sachet to an infested wardrobe changes nothing about the eggs and larvae already present.
Sealed storage works better because it removes access entirely. A garment inside a properly closed bag or box cannot be reached, regardless of what the surrounding room contains.
Interrupting the cycle is what ends it
The full life cycle runs over months, and larvae can feed for a long stretch before pupating. A wardrobe can look fine while a generation is already established inside it.
Sustained freezing or a hot wash kills eggs and larvae in an individual garment, which is why treatment has to cover everything in a space rather than the pieces with visible holes.
Vacuuming the wardrobe itself matters for the same reason, since eggs sit in seams, corners and carpet edges rather than on the garments alone.