control
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Wood rats, Neotoma spp.,
also referred to as "pack rats" or "trade
rats", are widely distributed over much of
North America. One or more species are found in
parts of most states with the exception of a few
of the north-central and Great Lakes area states.
They are also absent from most of the New England
area. Some eight species and many subspecies are
usually restricted to a given type of habitat,
but members of this genus occur from low, hot,
dry deserts to the cold, rocky slopes above timberline.
Wood rats are apparently attracted
to small, bright, shiny objects such as spoons,
small pieces of jewelry, broken bits of mirrors,
coins or other items, sometimes leaving sticks,
nuts or other materials in trade. The common names,
"pack" or "trade" rats, were
giving these animals because of these antics.
These characteristics are frequently the subject
of exaggerated stories from which it is difficult
to sift fact from fiction.
Wood rats are rat-sized mammals
with large ears, large dark eyes and fairly long
tail which is sparsely covered with hair or, depending
on the species, well furred with long hair. Their
fur is soft; dorsal fur is colored cinnamon, brown,
gray, yellowish gray or creamy buff; feet and
ventral parts are generally much lighter in color;
the tail is blackish or puff, paler on the ventral
surface. Wood rats are much larger than mice and
tend to resemble the introduced Norway rat or
roof rat in general size and shape. The head and
body length is about 7 to 8 inches and the tail
is 6-1/2 to 7-1/2 long. Their clean appearance,
soft fur and well-haired ears help distinguish
this native species from the Norway and roof rats.
Reproductive activity is most
pronounced in spring. One to five litters a year
are reported, with the number of young varying
from one to four, with two about average. This
species is not highly prolific and annual population
increases or decreases are not great.
Wood rats have been involved
in epizootics of plague and have been found infected
with tularemia. They are reservoirs of the trypanosomes
(parasitic, bloodinfesting protozoans) of Chagas'
disease. Their role in transmitting disease to
man is considered minor, although dead or dying
wood rats should not be handled with bare hands,
especially in plague areas.
Some species such as the dusky-footed
wood rat (Neotomafuscipes) are agile climbers
and often construct bulky stick dens or nests
high in the crowns of trees. More commonly, however,
dens are situated on the ground. Ground dens measure
3 to 5 feet in height and diameter; tree nests
are somewhat smaller. One animal may inhabit several
nests, and in good feeding areas a den may be
occupied for several years or a lifetime. Wood
rats live alone except when mating or rearing
young. The dusky-footed wood rat of the west is
semiarboreal and, when traveling between tree
nests, jumps squirrel-like from branch to branch.
Other lowland and desert-living species are essentially
ground dwellers.
Wood rats climb readily and
are chiefly nocturnal; occasionally they are observed
during daylight. Their food is largely determined
by varying local conditions and consists mainly
of a variety of green vegetation including grass,
leaves, fruit, nuts, small bulbs, bark, dry seeds
and fungi. They also may be attracted to human
food supplies in buildings or in outdoor camps.
When wood rats nest in buildings,
they may utilize available foods within the building,
but most often they continue to feed outside.
Visible ground trails 3 to 4 inches wide may be
evident from the nest to the feeding grounds.
In forest they clip young and debark older conifer
trees for food and nest building, and in backyard
or commercial orchards they will occasionally
clip young 1/4-inch diameter limbs from fruit
trees.
Girdling of small trees and
shrubs occurs but is not common. Rarely do they
become numerous enough to cause more than very
limited damage to flower or backyard vegetable
gardens. Nationwide they are considered a pest
of very minor occurrence; however, locally they
may be relatively significant pests.
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