Medicine: Why Rats Bite Babies

Rats bite men because they like human blood. Johns Hopkins’ Curt P. Richter, Ph.D., in the Journal of the American Medical Association, says he can prove it.

Dr. Richter’s interest was aroused when he noticed how many people came in to Johns Hopkins Hospital to be treated for rat bites. There were 87 in four years, most of them from the two-square-mile area surrounding the hospital, and Dr. Richter heard of 28 others who were bitten but did not come for treatment. Most of those bitten were babies under a year old. “One child was bitten on eleven different nights.”

Rat bites are serious. All of the Johns Hopkins cases had infections or pieces of flesh eaten away. Seven developed rat-bite fever.*

Dr. Richter gave three rats each a dish containing 139 grams (about 4½ ounces) of operating-room blood and serum. In less than 24 hours “two of the rats had eaten all of the blood and one had eaten 47 grams. When one considers that the average normal food intake of full-grown wild rats does not usually exceed 35 to 40 grams, the large intake of 139 grams indicates that the rats had a real craving for this fresh human blood.”

* In rat-bite fever, the original wound heals temporarily, later opens again, larger and more angry-looking, a rash develops, temperature rises to 103° or 104° F., falls to normal in a couple of days, then rises again in cycles which may recur for months. The patient may grow thin, have muscle pains, delirium, arthritis. Treatment is similar to that for syphilis and saves nearly every case.