Woodlice seem harmless. Many children actively seek out these bugs for an afternoon's entertainment. They have even affectionately nicknamed this potential pest, referring to them as pill bugs or roly polys for their habit of curling up into a tight ball every time they're touched. The bugs are able to protect their vital organs when they are tightly rolled up, but to the casual observer, woodlice in defence mode look more like pills or stones then insects. The tiny grey or black arthropods do not bite, so there is no immediate harm in handling them. However, if they are transported back to your home or garden their population can rapidly multiply. In large numbers, woodlice can have a devastating affect on any surrounding vegetation.
Sprinkle diatomaceous earth around your garden and around the perimeter of your home. Choose the type intended for gardening and not the type commonly applied to pool filters. The minuscule shards in the product will erode the exoskeleton of the woodlice. This will inhibit their ability to absorb fluid, leading to progressive dehydration.
Take active steps to reduce the amount of moisture in the affected areas. Woodlice are drawn to damp, dark places, and can frequently be found in basements, under logs and in plants both indoors and out. Do not over water your houseplants and reduce the frequency with which you water your garden. Place dehumidifiers and fans in any household areas were woodlice are frequently found.
Promote the development of animals that dine on woodlice. They are a favourite food source of frogs, toads, lizards and most birds. A few well-placed bird houses, a couple of chickens, or a trip to your local reptile supply house can serve you well.
Treat cracks, crevices and corners where woodlice have been seen with a commercial insecticide. The chemicals will kill any bugs in comes into contact with, but the solution is a temporary one. Insecticides will need to reapplied periodically; at least once every 2 weeks or immediately following a heavy rain.
Spread decomposing organic material around your garden. You can use leaves, grass cuttings, garden weeds, or fruit and vegetable peelings. Woodlice prefer decaying plant matter to fresh. By providing them with a ready supply of their favourite food you reduce the likelihood of woodlice devouring your plants.
Seal any holes or openings into your home with wood fill, caulk, patching cement, polyfill or duct tape. The choice of sealant should reflect the materials to which it will be applied and the length of time you require closure. Include areas around pipes, doorways and windows as these are common insect entry points to your home.
Treat any soil where woodlice are found with spinosad. This is an organic yard treatment that will repel woodlice without damaging plants or other forms of wildlife.