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

Caterpillars of Leptocneria reducta, LYMANTRIIDAE
on the march looking for more leaves to eat.

There are 3 basic reasons why caterpillars leave their foodplant:

  1. When disturbed they drop on threads to escape predation, and then have the job of finding their food again when the danger is over. They could be disturbed by violent winds or by the prescence of predators like birds or wasps.

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

  3. When they 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 get much further, it is necessary to establish what species they belong to. A help would be a description: length, colour, any patterns, hair distribution, number of prolegs? How do they move: loop or crawl? Other habits? A photo can be really helpful. What species of plant they were feeding on?

Link to
Frequently Asked Questions about Caterpillars

Australian Butterflies
Australian Moths

(updated 5 March 2007)