Ladybird beetles (as they are correctly known) are a moderately large family of beetles.
They are generally fairly small but the medium to large species, those around 5mm in length and brightly colored, are generally readily recognised as such.
What is less known is that there are many smaller species (down to around 1mm in length) and they are often hairy.
Most species are beneficial, feeding on invertebrate pests such as whiteflies (Aleyrodidae) and aphids (Aphidoidea).
There is one known exotic species in Australia (also found on other continents), the Asian Ladybird Harmonia axyridis.
For a substantial list and images of species found in Australia you should visit the
CSIRO's Ladybirds of Australia Web Site.