In Australia quarantine is taken seriously so they can avoid any infectious materials being brought in the country. If you carry any food, fruit, vegetables or seeds, any animal related products be prepared that these cannot be taken to Australia. If you happened to carry one of these you will be asked to discard it before entry. Planes are disinfected with smoking prior to landing. You will be asked to show your boots (if you carry one) and carefully remove all the mud / any soil stuck on it prior to entry. Border protection staff will examine your straw hat and wooden slippers too.