Venomous spider appears on the coast of Finland

Due to global warming, one of the most venomous spider species found in Finland — the yellow sac spider — has begun to spread more widely. This was reported by the scientific magazine "Suomen Luonto".

“A venomous spider is spreading in Finland — climate warming benefits the alien species,” the publication states.

The magazine notes that this spider is currently considered one of the most venomous among the species found in Finland. It was first detected in 2022 on Seili Island. Later, it was also encountered in other areas of the archipelago and along the coast. At the end of the summer of 2026, this species was also recorded on the Porkkala Peninsula.

The venom affects the human body

According to reports, the main population of the yellow sac spider is located in Central Europe.

The venom of this spider can cause severe inflammatory processes in the human body.

Four species of sac spiders are found in Finland. These are the common sac spider, green sac spider, striped sac spider, and curved sac spider.

Experts emphasize that it is not easy to distinguish these species from one another based on external characteristics.

Hides during the day, hunts at night

Yellow sac spiders are mainly active at night. After dark, they begin moving around to hunt various insects.

During the day, they hide inside dense, sac-like webs spun among low-growing plants.

Therefore, the probability of this spider getting caught in an insect enthusiast's, or entomologist's net, is much lower compared to some other spider species.