Are daddy longlegs the most venomous spiders?

This question comes from a popular urban legend and gets a couple of things wrong. First, true daddy longlegs are arachnids of the order Opiliones and are not spiders at all. They also lack venom altogether, so there’s that. The question is really about the common cellar spider (Pholcus phalangioides), sometimes called the daddy longlegs spider. Unlike its round-bodied namesake, this true spider has two visibly distinct body segments, which are characteristic of spiders, and...