Sticky feet allow flies to walk across the ceiling

Press, 12 March 1985, Page 12

Sticky feet allow flies to walk across the ceiling

Flies, such as those which have been bothering households in the past few months, can carry deadly diseases. Though tiny, houseflies can make humans very sick, as they can carry typhoid or dysentery. The feet and body of a fly are covered with bristling hairs, and its tongue is coated with sticky glue. This means that dust and dirt will cling to the fly. Because the housefly will look for its food anywhere, including garbage and sewage, the bacteria of various diseases may be in the dirt and dust that stick to the fly-

Then if the fly touches food, the bacteria may enter the bodies of the people who eat that food.

Houseflies do not eat solid food because they have no teeth for biting. When a fly lands on food it spreads saliva which turns a tiny section of the food to a liquid. It then sucks up the saliva through funnels in its tongue. Houseflies like to breed in places where there is moist, decaying matter, like rubbish piles. The females lay about 100 to 150 eggs and from each of these comes a slender, worm-like maggot.

After about 10 days the maggot changes into’a fly. Ten days later the fly mates, and soon after the new fly lays a batch of eggs and the cycle continues. Under ideal conditions, flies have an enormous rate of reproduction. It has been

calculated that a single pair of houseflies could produce 191 trillion (191,000,000,000,000.000,000) descendants in four months if all survived and reproduced. The remarkable physical characteristics of the fly enable it to perform feats such as walking upside down on the ceiling. Even with powerful glue on our feet, humans would find this rather difficult. But nature has provided flies with sticky pads on their feet which allow them to walk across the ceiling with ease.

When walking upside down the fly picks up two legs on one side and one on the other, always leaving its three remaining legs firmly affixed to the ceiling.