166 RELATION BETWEEN ANTS. 
there observe some sentinels doing daily 
duty, that is to say, opening and closing 
the gates of the ant-hill morning and 
evening ; sometimes these asylums be- 
come little colonies, which maintain a 
close connection with the principal ant- 
hill; they are different habitations, com- 
mon to the same ants, serving them for 
places of refuge on any derangement of 
what we might term their capital. * 
I have often seen in fir-forests, very 
large ant-hills contiguous to each other, — 
communicating together, like cities of 
the same empire, by regular tracks : — 
these tracks are sometimes as much 
as a hundred feet in length, and seve- 
ral inches in breadth; they are not 
produced by the passing and repassing of 
the ants, several thousands of whom are 
in motion each day from one ant-hill to 
the other, but are excavated by the ants 
* Mr. Kirby mentions a similar circumstance. 
In speaking of a colony of that species, termed 
the Hill Ant (F. rufa): he informs us, that their 
nest was one of considerable magnitude, and that 
at certain distances from it, they had established 
six or seven smaller settlements. — T. 
