jlindy ,
Moles live their lives underground , they spend 99% of their life below the soil. Moles DO NOT have holes open to the surface. If you poke a hole in a mole's tunnel , they will repair it.
Now , if you are seeing OPEN holes , you are dealing with a different animal. If the holes are about the size of a US quarter to the size of a golf ball , you have Voles and/or shrews . If the holes are larger than a golf ball but smaller than a baseball , you have chipmunks.
Chances are you have Voles. Voles are very common in mulch beds.
Good news , control is easier than moles.
Voles feed on plant life , seeds , roots etc. Moles are insectivores - no plant material.
There are two ways to correct this - Trapping or poison.
To trap the animal you will need about a dozen regular mouse traps. Buy Victor brand mouse traps , look for the ones with a yellow plastic trigger not the ones with a small metal trigger that is copper plated. The one with the yellow plastic trigger only costs a few pennies more than the ones with a metal trigger. The yellow plastic trigger is much easier to set and has a scent embedded into the plastic to lure the animal to the trap.
You will need at least a dozen traps even if you only think you have 1 animal. This gives the animal multipliable chances to get caught plus you will catch it much quicker than if you only used a couple traps. Don't use some off-brand cheap trap , get the Victor brand , they only cost a tiny bit more than some crappy copy. If you use a cheap trap , it may not catch the animal and they get away. The animal has now learned what a trap is and has become ' trap shy '. Even though the yellow plastic trigger has a scent embedded in the plastic , I like to add just a tiny bit more scent to improve my chances. Put a small amount of peanut butter on the trigger about the size of a matchhead. Do not over bait as this will give the animal a chance to steal the bait without getting caught. Using some peanut butter the size of a matchhead will make the animal work hard to get the bait and will cause him to trip the trap instead of stealing the bait.
Set the traps very close to the holes in the mulch. Cover each trap with an overturned flower pot or similar object with a hole cut into the side for access. This will keep you from catching songbirds or having your dog stick his nose where it does not belong. I have used plastic containers like you see for sale that are intended for a couple uses and then thrown away. Place a rock or other weight on the top to prevent the plastic from blowing away in the wind. Covering the trap also has a couple advantages , it keeps the bait fresh and small animals like voles and mice feel safe hiding under them which will increase your chances.
To poison the animal use any standard mouse or rat poison. You can get pellets or blocks. Blocks work better as the animal has to gnaw pieces off in order to take the poison away instead of stuffing it's cheeks to carry away to store for later consumption. Place the blocks into the burrow so your dog or another animal cannot readily get to eat the bait. BTW-Mouse and rat poison rarely has any effect on dogs or cats unless they eat several pounds.
Poison takes a little while to have an effect as it is a cumulative effect as the poison builds up in the animal's system.
These tips will only work if you have voles , shrews or mice. The poison will work on chipmunks but to trap a chipmunk you will need a larger trap like a rat trap.
This will not work for moles , that is a completely different process.
If you are interested in hiring a professional , I know of a guy in the St. Louis area who is very good and highly recommended.
Jeff Holper - Holper's pest control.
http://www.holperspest.com/home.nxg