In the UK, up to 50% of the homes are' believed to be infested with woodworm. In the case of the common furniture beetle (Anobium punctatum), which causes up to 80% of the damage, it lays eggs on unplaned joists and floorboards. The grub bores for three years and then pupates and flies away. The many other kinds of wood-boring beetle cause the remaining 20% of the damage.