Why are all these caterpillars invading my house?
Don Herbison-Evans,
Stella Crossley

moth eggs laid on an indoor wall
Leptocneria reducta, LYMANTRIIDAE

Some caterpillars are found in houses because their mother moth flew in and laid eggs there.

Some caterpillars live on walls and in crevices in the house, feeding on mould or algae.

Some caterpillars feed on the seeds and fruit that we bring into the house to eat, and may have been laid as eggs, for example in flour, rice, nuts, dried fruit, or muesli.

Most caterpillars feed on leaves outdoors. There are 3 basic reasons why these caterpillars leave their foodplant and come into the house:

  1. When disturbed they drop on threads when they are are disturbed by violent winds, or by the prescence of predators like birds or wasps. When the danger is over, the dropped caterpillars go walkabout seeking their food plant again.

  2. If their foodplant becomes substantially defoliated, caterpillars will go walkabout to seek more sustenance.

  3. When caterpillars are ready to pupate, they go walkabout to find a nice sheltered crevice for their long sleep.

Caterpillars of Ochrogaster lunifer, NOTODONTIDAE
on the march looking for somewhere to pupate

To stop particular caterpillars coming into or found in the house, it is necessary to identify the species they belong to. Then you can establish whether it an accidental or deliberate incursion. To identify the species: a photo can be really helpful. Also a description would also help with information on its length, colour, any patterns, hair distribution, number of prolegs, how they move (loop or crawl), any other habits, and what were they were feeding on.


Australian Butterflies
Australian Moths


(updated 5 March 2007, 23 November 2013)