The Portuguese was introduced to Australia and reproduces in Autumn and early Winter. Once they lay their eggs they will be on the move, in large numbers.
Mature females lay around 200 tiny eggs in a small hole they have made in the soil, and once hatched are found to move into homes; due to the attraction of the lights at night.
They are not a threat to human health, however they may destroy vegetable patches and infest houses. They can release a pungent and distasteful yellowish secretion which may stain your skin, clothing or irritate your eyes if rubbed after being in contact with them. Millipede treatments are available and involve the internal and/or external areas of the building and roof voids (if applicable).