THE RAT IN RELATION TO SHIPPING. 



By William C. Hobdy, 

 Passed Assistant Surgeon, Public Health and Marine-Hospital Service. 



Since men first went down to the sea in ships the rat's voyage- 

 making tendencies have been known, and their fecundity is as well 

 established as their fondness for travel. The record does not state 

 that there were more than a pair on the ark at the beginning of her 

 voyage, but the chances are better than even that her skipper began 

 that voyage with more rats than his manifest showed; but whether 

 he did or not, we can be sure he had more at the end of the voyage 

 than at the beginning. Whether or not succeeding generations in- 

 herited from their forbears on the ark this well-known wanderlust is 

 undetermined, but it is a fact that the intimacy and companionship 

 established and begun then have been persistently maintained by the 

 rat ever since. His travels have been coextensive with man's, until 

 to-day there is not a port on earth where the rat is not present. Any 

 exception to this statement simply proves the rule. The rat is cute; 

 he knows when he is well off and his absence from a port does not 

 prove that he has not been there, but that he has been too intelligent 

 to follow man ashore. In establishing this shipboard intimacythere 

 has been no "by your leave" courtesy on his part either; he goes 

 without consent — against orders, even — and man's ingenuity has as 

 yet discovered no effective means of keeping him off. This is not 

 surprising when the rat's ability as a rope walker is considered. I 

 have seen a rat gallop with all appearance of enjoyment along an 

 inclined electric cable from a church steeple on one side of a street 

 into the second story of a hotel on the other. Others have been seen 

 traveling along the telephone wires from house to house, and on ship- 

 board they frequently have runways on small pipes along which they 

 scurry in perfect security. When a ship is fended off 6 feet from the 

 dock and her gang plank is lifted or guarded she is still freely accessi- 

 ble, because all her mooring lines are only so many highways along 

 which rats can and do pass with ease and in perfect safety. 



This fondness for ships and sea travel is shared by the various 

 species of the rat family, but the Mus norvegicus has earned the repu- 



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