Well, if you're sure there are no gophers in your region (so maybe
groundhogs, though they're usually more solitary & don't ordinarily have
multiple deep entrances as you describe, so I don't really suspect a
groundhog, but maybe), a quick phone call to animal control describing the
nature of the holes would likely get you a definitive diagnosis of
species, & advice on control. In the meantime, I'll repost an old bit
about groundhogs cuz why not. Also, an added rather odd note, a usenet
discussion erupted a couple years back in this newsgrkoup in which a
couple folks were swearing up & down "it worked for grampa" or they'd
tried it themselves, they'd eat a big steak dinner then take a dump in the
groundhog holes, which smelled like the presence of dangerous carnivores &
the groundhog moved away. I've no idea if there's truth to it but it does
have an appealing "natural solution" ring to it.


[REPOST OF GROUNDHOG & PRAIRIE DOG POST]

I lived with a prairie dog for a while. His name was Woodrow. Though they
are not notable climbers, he figured out a bag of peanuts, from which he
received very occasional treats, was kept on the top of a seven-foot-tall
shelf. He managed to get up there one day when I was letting him roam free
in what I thought was a "prairie dog proofed" room, & by the time I came
back in the room, he'd eaten the whole bag. Which gave him one hell of a
stomach ache & diarrhea & cost me a vet bill.

This was my room mate's pet but as she was gone a
lot, I was his defacto caretaker. He was a TERRIBLE pet for
destructiveness & odor & when my roommate moved out I was SO relieved not
to have Woodrow around anymore. I lived with him for nearly two years
though & have as many good memories of his charming behavior, as of bad
memories of stuff he ruined & messes he made & visitors who wanted to know
what that smell was.

Anyhow, in gardens, moles are insectivorous & cause no harm to a garden,
are actually beneficial, & it bothers me people are so insistent on
killing them. But groundhogs are vegetarians & will devour many things in
the garden. I would almost certainly attempt to accomodate a woodchuck or
the like even so. I mean, if I can forgive a prairie dog for chewing up a
rare book, I'm sure I could forgive a woodchuck for eating the flower
buds. But where I presently live I'm not likely to be tested on that
score (no groundhogs in this town).

As a big rodent fan myself, I've read several articles about people who've
befriended their garden woodchuck with quite a lot of success. They tend
to impact gardens a lot less if you feed them at predictable times of the
day, as they're lazy buggers at heart. Of course, having ONE semi-tame
woodchuck might become pretty easy, but if it became a happy extended
family, that could be big trouble. Here are a couple Pet
Groundhog/Woodchuck websites:
http://www.geocities.com/SiliconVall.../bob_lutz.html
There are lots of links at that site. Plus this groundhog lovers website:
http://www.hoghaven.com/
which has a photo section to die for, cute cute cute.

-paghat the ratgirl

PS: The following is quoted verbatim from a "Woodchucks in the Garden"
fact sheet including humane control measures:

The groundhog, or woodchuck, is a large rodent, about two feet long,
including its bushy tail. It has a compact, chunky body supported by
short, strong legs. The forefeet, which have long, curved claws, are well
adapted for digging. The coarse fur is gray on the upper body and
yellowish-orange on the underside.

Groundhogs prefer to live in open fields, woodlands and hedgerows. They
dig extensive burrows with two or more entrances. These burrows are
commonly located in fields, pastures, along fence rows, stone walls,
roadsides, and even at the bases of trees. Groundhogs feed on a variety of
vegetables, grasses and legumes. Some favorite foods are peas, beans,
carrot tops, alfalfa, clover and grasses. Early morning and evening hours
are the groundhog's preferred feeding times.

Control: Needless to say, groundhogs living near vegetable gardens and
other choice plantings can be real pests. Control measures are limited in
residential and suburban areas. Wire fencing discourages them sometimes.
Live-trapping may also be effective; bait the trap with apple slices or
vegetables such as carrots or ears of corn. Another method is flushing the
animals from their burrows, then filling the entrances with large rocks.
Admittedly, none of these solutions will take care of the problem
permanently, but they may reduce the damage groundhogs do.

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/