All spiders are predatory and feed upon living prey. Often voracious eaters, they can be beneficial by reducing insect populations. Therefore, large numbers of spiders can be a sign of a more extensive pest problem. Spiders affect human health in three primary ways: annoyance or fear, allergic reaction, and with their venom. Neurotoxic venom travels the nervous system and can cause abdominal cramps, sweating, hypertension, nausea, leg cramps, vomiting, and in severe cases, breathing difficulties, heart irregularities and even death. Cytotoxic venom causes tissue death, generally located at the site of the bite. Young children and the elderly are most at risk. Spiders seldom bite people, and though all possess poison glands, few are considered harmful. However, some spiders are of concern due to the dangerous nature of their bites. Widow spiders, usually black with a reddish hour glass shaped marking, cause more apprehension than any other spiders. The Brown Recluse spider is not common in Florida, but can be reported due to transport of commerce or domestic household goods.