where does the spray from a skunk come from
Skunk Skunks are notorious for their anal scent glands, which they can use as a defensive weapon. They are similar to, though much more developed than, the glands found in species of the family Mustelidae. Skunks have two glands, one on each side of the anus. These glands produce the skunk's spray, which is a mixture of sulfur-containing chemicals such as thiols (traditionally called mercaptans), which have an offensive odor. A skunk's spray is powerful enough to ward off bears and other potential attackers.[citation needed] Muscles located next to the scent glands allow them to spray with a high degree of accuracy, as far as 3 m (10 ft). The smell aside, the spray can cause irritation and even temporary blindness, and is sufficiently powerful to be detected by a human nose up to 5.6 km (3.5 miles) down wind.[citation needed] Their chemical defense is effective, as illustrated by this extract from Charles Darwin's Voyage of the Beagle:
Bubonic plague Bubonic plague is an infection of the lymphatic system, usually resulting from the bite of an infected flea, Xenopsylla cheopis (the rat flea). In very rare circumstances, as in the septicemic plague, the disease can be transmitted by direct contact with infected tissue or exposure to the cough of another human. The flea is parasitic on house and field rats, and seeks out other prey when its rodent hosts die. The bacteria remained harmless to the flea, allowing the new host to spread the bacteria. The bacteria form aggregates in the gut of infected fleas and this results in the flea regurgitating ingested blood, which is now infected, into the bite site of a rodent or human host. Once established, bacteria rapidly spread to the lymph nodes and multiply.