Harvestmen, commonly known as daddy long-legs, belong to the order Opiliones, and no, they are not spiders! They are an ancient order of arachnids that began showing up in the fossil record about 410 million years ago, and have not shown many changes in their morphology in nearly 200 million years. There are many myths that persist around harvestmen, the most pervasive being that they are “the most venomous spider in the world but their fangs are too short to bite humans.”
Again, not spiders. In arachnid terms, they’re not even closely related.
There are around 6,500 described species of harvestmen (more described species than mammals) and none of them have venom glands. In fact, they don’t even have fangs. Their chelicerae are more similar to that of a scorpion; small, claw-like appendages that they use to break up their food into small chunks. Remember, spiders have a “sucking stomach” and must use digestive enzymes to liquefy their food before they consume it. Harvestmen have no sucking stomach, no fangs, and no venom.