The western Black Widow Spider inhabits areas of the US, parts of Mexico, and Canada, including Vancouver Island.
They typically prey on a variety of insects, but occasionally feed on other arachnids, as well. It waits until prey has been trapped in its web, before darting out of its den to bite & inject it with venom, and then wrap it up in silk.
The venom from these spiders takes about 10 minutes to take effect. It holds its prey tightly until all movement has stopped, and then injects digestive enzymes into the initial bite wound. The spider then carries its victim back to its retreat, before feeding.
This spider, although small, has extremely dangerous venom, said to be more potent than that of a cobra. It is rare for a healthy human adult to be injected with a fatal dose from the black widow spider. Generally, bites will result in a large swelling around the wound site, followed by nausea, muscle aches, and breathing difficulties.