european black widow (latrodectus tredecimguttatus), a female spider sits in her nest with a cocoon of eggs

animal arachnid arachnida arachnophobia araneae araneomorphae arthropoda bite black caution chelicerata cocoon danger dangerous deadly egg eggs european hunter karakurt killer latrodectus mactans mediterranean nature neurotoxic poisonous poisonousness sacks spider spiders steppe theridiidae toxic tredecimguttatus venomous widow wildlife