|Most spiders found in Ontario homes are harmless to humans, so relax.|
The spider that I called a daddy long-legs is also called the harvestman and I understand it is not a true spider. I think the term daddy long-legs fits the harvestman more than the cellar spider and so I'm staying with my terminology.
There is a myth that a daddy long-legs (cellar spider) has the most potent venom of all spiders but because it is unable to pierce human skin, it is harmless.
This myth was tested on Myth Busters and it was busted — twice. It seems the spider was able to bite through Adam's skin but he reported nothing more than a very mild, short-lived burning sensation. Analysis of the venom proved it didn't approach the potency of the black widow spider.
Apparently one story isn't a myth. Cellar spiders do hunt and kill the dangerous-to-humans black widow.