Red Back Spider (related to the Black Widow). Warning - poisonous! (Definitely unfriendly). Likes to live in sheds and under patio furniture. Strongly recommend routine spraying by surface spray insecticide (e.g. morteen). It makes the surface poisonous for insects for a few months. This one was established under an old piece of wood in the yard. The "balls" contain eggs which will hatch into hundreds of babies. I normally crush them but I have read that freezing them in the freezer is the best way to destroy them. Their webs are particularly strong but messy, not like the more usual architectural marvel that we see strung between trees or across the path. You can hear them crackle as you break the strands.