296 REPORT OF THE HARVARD AFRICAN EXPEDITION 
MURIDAE Old World Rats and Mice 
Rattus rattus rattus (Linné). Black Rat 
Mus rattus Linné, Syst. Nat., ed. 10, vol. 1, p. 61, 1758: Sweden. 
Size large, ears large, tail longer than head and body; above black, slightly more slaty below, 
feet sometimes white. 
The European Black Rat has been introduced in Liberia and is occasional, 
but less abundant that the Gray Rat. Biittikofer secured specimens at Roberts- 
port and Miller records four from Mount Coffee. We had several brought to us 
that were taken in native houses, but preserved only one, that came into one of 
our tents on the Du River. It had probably wandered along the path to our 
camp from the bungalow of the local superintendent of the plantation, a few 
hundred yards away, whose chicken house was much troubled by rats. This 
specimen is not as deep black as typical black rats, but a dull grayish, overlain 
above with abundant black hairs, and showing in a good light a faint tinge of 
brownish. Possibly the black individuals here interbreed with the gray, and the 
deep black coat seen in the Black Rat of New England becomes diluted, or these 
may be merely melanistic individuals of the next. 
Rattus rattus alexandrinus (Geoffroy). Roof Rat 
Mus alexandrinus Geoffroy, Cat. Mamm. Mus. d’Hist. Nat. Paris, 1803, p. 192: Alexandria, Egypt. 
A rat with large ears, and tail longer than head and body, scaly; above dull brownish, due to a 
mixture of long black hairs with others having a subterminal yellowish tip and gray base; below 
soiled gray. 
The introduced Gray or Roof Rat swarms about the native villages, where 
it lives chiefly in the thatched roofs of the houses by day, and at night ventures 
forth in search of food, so that we found it unsafe to leave any specimens exposed 
during the night lest they be eaten or carried off. The native houses are usually 
circular, with a high and steeply pitched roof of many poles, covered with a deep 
thatch of palm or other broader leaves. A rough ceiling of cross-poles forms a 
sort of attic space, sometimes used for storage, but usually in the “palaver 
kitchens” in which we camped, empty. This roof makes an excellent refuge for 
the rats. On one occasion a very young one dropped through the chinks of a 
roof on to our table below. Exactly how these rats have reached even remote 
villages separated from their neighbors by miles of forest is difficult to see unless 
they have been transported by persons carrying baggage or perhaps they follow 
along streams and paths to a certain extent. No doubt they often come into 
competition with the Multimammate Rats, for these too are house rats in this 
part of Africa, coming freely into the huts and “palaver kitchens” or public 
gathering houses. Thus at Gbanga, we were more than once disturbed at night 
by the scuffling and squealing of rats fighting on the floor near our beds, and 
although we did not identify the combatants, there is little doubt that they were 
these two species, for traps set about the inside of these houses caught the two 
kinds only. Biittikofer’s Mus rufinus is probably this. At Paiata a small 
python was brought in, the stomach of which contained a Roof Rat. 
