apart from causing itchy bites, mozzies can carry a range of viruses which can cause prolonged illnesses - but thankfully there is no malaria and almost no dengue fever in Australia (apart from northernmost parts of Australia which can have dengue outbreaks)
Australan mozzies are active at temperatures above 10-12degC and are most active on humid warm evenings with minimal breeze
avoid camping in high mozzie areas:
whilst active wear clothing is great for hiking, the thin material closely applied to the skin will NOT stop mosquito bites - wear loose fitting light coloured clothing with full coverage of your body instead if mozzies are an issue
in heavy mozzie areas such as the Murray River, mozzies tend to be active during the day as well as night but in most areas, dawn and dusk are peak periods for most Australian mosquitoes
insect repellents are generally recommended for mozzie areas such as:
Nature's Botanicals
30% DEET products
permethrin clothing
insect proof shelters are critical and ensure there are no lights on inside when you open the doors to avoid encouraging insects coming in
camp fire smoke does seem to deter most insects but this should not be relied upon
use orange or red lights in your camp area to reduce attracting insects of all kinds to bright white or blue lights
area-based insect repellents can also be very useful at night such as:
Thermacell products
for hikers check out the Thermacell Backpacker Repeller - uses standard butane gas cartridges which you use for your cooking stove
for other campers, check out the lithium battery powered Thermacell E55 - battery lasts 5.5hrs but can be charged whilst running via USB for all night use