Myth: The daddy-longlegs has the world's most powerful venom, but fortunately its jaws (fangs) are so small that it can't bite you.

Fact: That is a full-fledged Urban Legend, with no basis in fact whatever. This legend is so widespread that many people believe it who should really know better, including some teachers and TV documentary producers.

Three different unrelated groups are called "daddy-longlegs." Harvestmen have no venom of any kind. None at all! Same with crane flies . Pholcid spiders have venom (like almost all spiders) but there's nothing special about it; in fact, a recent study showed that pholcid venom is unusually weak in its effect on insects. This myth is debunked at greater length on Rick Vetter's website.