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used the rock piles at ground level during the day. R.. exulans were 
relatively rare on Swains Island, a wet island with lush vegetation. 
They were found in old buildings and sheds, under logs and in piles of 
discarded coconut husks. According to the villagers, dogs and cats on the 
island kill rats frequently, which may account for their low population in 
comparison to Swains were cats are rare. On Hull Atoll, a wet atoll that 
is not inhabited, rats were very common. They occurred in the deserted 
village as well as in undisturbed coconut forests. An average of one rat 
was seen for every twenty square feet of ground area. Only one cat was 
sighted on the island. In the vicinity of the village, rats occurred on 
roofs, walls, and floors of huts and utilized stone walls or rock piles, when 
available, as hiding or nesting places. A nest of straw and grass 
containing two embryos was located under a rock. In coconut forests, 
rats built nests and hid under piles of coconut fronds. 
R. exulans were more active nocturnally than diurnally. On 
Swains, a maximum of 2 6 rats was counted in one hut at night as compared 
to a maximum of six during the day. On Birnie, only two rats were sighted 
in the open during the day; the rest were found in rock piles. 
Rats eat a variety of foods. On Hull Atoll, rats were observed 
eating breadfruit, melons, seeds, coconut meat, and 1 Polynesian gecko 
( Gehyra oceanica ). On Swains Island, rats also utilize fruit; on 
Birnie, rats rely on such succulent plants as Sesuvium . 
Of l 4 specimens of R. exulans collected from Birnie, six males 
