Pest Advice - Woodlice

What are they?


Adult woodlice are slate grey in colour, have seven pairs of legs and are between 2.5 and 18 mm long. They are crustaceans and are closely related to crabs and lobsters. They evolved to live on land but still need damp conditions.

Woodlice avoid light and are active at night, feeding mainly on dead or decaying plant material. By day, they are usually found hiding under stones, plant debris or damp wood. In autumn however they may enter homes through air vents or under doors in search of shelter for the winter.

Woodlice do not harm people or damage buildings. 

The female lays eggs in a pouch underneath her body. After about three weeks, the eggs hatch and young woodlice emerge. The young look like smaller versions of the adults and regularly shed their shells as they grow.

In the UK woodlice breed during the summer months only, producing between six and two hundred young in a season and have a lifespan of between one and four years.

Can I treat them?

Woodlice gather in large numbers in dark, damp places, such as under decaying wood or plant debris. Removing potential sheltering places away from your home can help stop woodlice from entering your house.

You can apply a barrier treatment using a suitable insecticide* which has been cleared for use against wood lice or in spray form or a dust applied to the outside walls of your home. Make sure you treat any small cracks and gaps there may be, in particular the gaps around steps, air vents and any damp areas.

*Always refer to the product instructions before use and follow these at all times. 



Last Updated on Wednesday, May 8, 2024