Redback spiders are black spiders with a red stripe on their abdomen found throughout Australia. The females can be up to 1 cm while males are smaller. They build untidy webs near the ground to catch insects and small animals. Females live for 2-3 years and guard egg sacs containing hundreds of eggs. Their venomous bite can cause nausea, vomiting and pain in humans but deaths are rare. Seeking medical care is recommended for any redback bite.