A relative of the infamous Black Widow spider, the redback is so named due to the red stripe that is on the abdomen of the female members. In contrast to the Sydney funnelweb, it is the female, rather than the male of the species, which is the most dangerous to humans. Generally found in dry, dark, and small spaces it iss usually a good idea to have a look into your letterbox before reaching in to get the post. They live all over Australia but are most common in the warmer regions as, like most people, they prefer the warm to the cold.
While they generally prefer to eat small insects due to their own small size, only 1cm for the large females and as small as 1mm for the males, they can capture even small lizards in their web.
However, unless you stick your hand directly into a redback web you are unlikely to receive a bite as redbacks prefer to stay close to home.
Symptoms of a Redback bite include very bad pain,, nausea, vomiting, sweating and muscular weakness. While there have been no recorded deaths due to redback bites since the introduction of antivenom, prompt treatment is still necessary.