A beachfront home in Woonona has been covered in a swarm of Plague Soldier Beetles.
The roughly one centimetre bugs can be seen mating and writhing across the concrete walls and windows.
The omnivorous beetles are found throughout south-eastern Australia and feast on other insects and plants.
According to the CSIRO, it is not uncommon for swarms of these creatures to turn up without much warning.
The bugs can descend in large numbers on plants and structures, but generally seem most interested in copulating and sucking nectar from flowering trees. According to the Australian Museum, one study found that 92 per cent of beetles in an infestation were found to be getting it on with one another.
This behaviour usually occurs during spring, summer and autumn.
While the beetle can secrete a poisonous venom to deter predators and protect eggs, the liquid is not harmful to people.
Warm and humid conditions are known to bring out the creepy crawlies in the Illawarra, and experts have asked residents to let the creatures be, and avoid the needless use of bug spray.
Our news app has had a makeover, making it faster and giving you access to even more great content. Download The Illawarra Mercury news app in the Apple Store and Google Play.