You got yourself one cute little weasel, that's for sure!  If your body
measurement was 4-6 inches MINUS tail, the beastie is a short-tailed
weasel, or ermine (_Mustela_erminea_).  Females are about 4-5 inches long,
males about 5-6 inches long, and the tail shorter than the body with a
black tip.  You probably saw this.
 
If the measurement was body AND tail, and the was tail was very short with
NO black tip, then the beastie was a least weasel (_Mustela_nivalis_).
 
My guess is you saw a female scrounging cat fur to line it's nest.  It is
likely to only be only about 6 months old or so, but full grown and living
on its own.  They eat mice, rats, small snakes, insects, frogs, and will
climb trees to raid bird nests.  They also go for high quality cat food,
just like ferrets.  Since you are in upstate NY, come winter and the weasel
will turn completely white except for the black tip of the tail.  Assuming
it lives that long; ermine are prey for cats, dogs, and owls, among others
and have a life expectancy in the wild of about 9 months.  They have a high
energy cost, so can easily starve to death.
 
If you move very slowly and carefully, and use binoculars, you can probably
find her nest.  I am sure that the weasel would appreciate a dead mouse
left nearby (live it just before dusk).  Because my house and human
activities disrupt my immediate local environment, I always suppliment the
weasels (they live in old logs behind my home) with mice and in the winter
with chicken gravy, although the skunks and raccoons figure it out and
start showing up as well (I also feed the local birds and squirrels and go
through 6 suet squares, 10 lbs of bird seed, 5 lbs of cracked corn and 5
lbs of sunflower seeds a week!  I fill 6 feeders at night, and by dusk the
next day, they are empty.  I get flocks of Grackles, Cardinals, blue birds,
blue jays, 4 different woodpeckers, and many, many more.  This year alone,
I have counted 34 species of birds in my backyard).  The weasels, also
ermine, eat the local pests and are a delight to watch in the early morning
and evening.  Mine "know" me, and will actually bounce up to see if I have
a mouse.  There are three, and one will actually take the mouse from me,
while the other two wait for it a few feet away.
 
Except for food supplimentation, I do not molest or worry the birds and
animals in any way.  I do put out bird nests, as well as fiber for the
weasels and fiber and grit for the birds, but I do not attempt to hold
them, capture them, or cause them any harm.  Weasels are wild animals,
and as cute as they are, possession may not only be illegal (They are
classified as furbearers), but bad on the animal.  You are very lucky to
have one so close.  Watch it carefully and you can see many of the
behaviors so endearing to our little ferrets.
 
Bob C and 16 Mo' Waskahwe Weezuls
[Posted in FML issue 2732]