CHELICERATA/ARACHNIDA
The best-known members of the class Arachnida, spiders are effective predators that use a variety of techniques to capture their prey. While many spiders create webs that snare their meals, others have excellent vision to chase and seize smaller creatures.

The poisons that spiders use to capture prey are generally not toxic to humans. One exception is the black widow spider, one of the most dangerous spiders in the United States. Its neurotoxic venom acts to block healthy transmission of messages from nerves to muscles, resulting in severe pain, nausea, and other symptoms.

Scorpions, ticks, and mites are other members of the class Arachnida. Scorpions kill their prey with a poisonous stinger located at the end of their extended, segmented abdomen.