Africa has plenty of mosquitoes, and plenty of diseases spread by mosquitoes. But Ebola is not one of them.

Only female mosquitoes bite, and they do not fly from person to person, biting. They hunt for blood only when ready to lay eggs. (At other times they, and males, live on plant nectar.)

When a mosquito sucks blood, its abdomen swells, and it immediately finds rest on a wall or tree for hours or days to digest the blood and let it nourish her eggs. Then the mosquito flies around seeking water in which to lay the eggs. Only after that does it look for another meal.

Mosquito-borne diseases — malaria, yellow fever, West Nile virus, dengue fever, chikungunya and elephantiasis — have slowly merged into this feeding cycle through evolution. Mosquitoes are not born with the diseases; they're picked up from humans. Then the disease has to survive the digestive process and get into position to infect the next human. In the case of malaria, which kills more than 600,000 people every year, parasites in the blood stored in the mosquito's gut spend up to two weeks changing into five forms. Two of those forms "mate," creating a final form that migrates through the mosquito to her salivary glands.

When mosquitoes bite, they inject saliva, which contains anticoagulants so they do not get clots in the thin proboscis, or biting mouth. Ebola can't get into mosquito saliva, so mosquitoes don't transmit it.

New York Times