What Could These Pests Be? (Seattle, Vancouver: hoa, work, house)

[Quantum]

Hi,

I recently moved to North Seattle, to a rent-house near Lake WA. I'm on a lot with large old-growth trees.

On warmer days, these clumps of dirt build up in random places on the yard; sort of fluffy mounds of dirt, as if some animal is digging under there and building up the detritus. There's no hole, just a fluffy mound of dirt. Any idea what this could be?

Also, the house is on a pier and beam foundation. There are two holes where vents have been pulled out, and I've been hearing a mammal under there in the past two weeks. It would chew on the substructure with a loud CRUUNCH, as if it's the size of a medium dog! I presumed it's a rodent, as it was gnawing; maybe a nutria.

Last night I was awakened by a ferocious fight going on under there at 1:00am. I could only make out one animal growling and fighting, but I know there were two. They were roiling and continually bumping their heads on the substructure like mad, shaking the floor for an hour. Then they went at in bursts, obviously exhausted. Finally one of them left.

My theory is one of that species took up residence and had babies, because I heard two pups down there squeaking periodically during the fight (as if to say "I'm here"). As time went on, I only heard one squeaking. Toward the end of the fight, none squeaking, and no squeaking since.

The second mammal arrived last night, which I believe must be the same species, as most other species would wisely escape a fight like that. The second mammal probably wanted to take over the space. After the fight was over, I could hear the remaining one wheezing and snorting to just get breaths, for the next hour.

This morning I looked in the foundation hole (which I hadn't prior blocked) with a flashlight. There's only a foot of crawlspace, but at the other side of the house I saw two reflective eyes looking back at me and moving around. They were wide-set, like a wolverine. I bricked up the hole, so it is now blocked in. I expect it to either burrow out, or die under there and stink up the house for several months. It does not seem to be a strong digger, as it made only a half-hearted attempt to dig at the other foundation hole which I'd prior blocked.

I've researched Seattle wildlife, and surprisingly can't find any reference of what might be around here. Only one wolverine's been trapped in WA for many years. Maybe it's a badger, but the eyes seem too far apart. Not a meerkat, beaver, or nutria.

Does anyone have any idea what these critters are?

[yzucker]

the mounds sound like gophers

[Quantum]

Hm. I should have said the dirt piles are pretty small, like 2" to 4" in diameter, and no visible hole. Surely not ground-crabs, 200' from the lake? Giant ant-lions?

I bricked up and buried the major hole to get under the house, and the (wolverine?) found another vent exit. So I put two medium rocks covering the hole. That afternoon, one of the rocks had been moved aside. Then yesterday I put a cinderblock with holes filled with dirt to cover it, and for good measure put two medium rocks on it for more weight. The critter was under the house at that time.

I woke up last night hearing it struggling and growling, I presume to try and get out for water and food. It then stopped and just *growled* with every breath until I went back to sleep. It is a mean little bugger. This morning the very heavy cinderblock had been moved aside! I couldn't believe it.

Why it would keep coming back, I don't know, unless it still had live young under there, but I haven't heard them. I'll heavily fortify the hole today. Then maybe it'll spend its time prowling around the outside of the house and maybe bite me, but I have a pellet gun. Better me, than some old lady, especially because I'm as mean as that animal.

[Ryan]

They're moles. Pretty easy to trap with a bucket. Check around on the internet for specifics.

[Quantum]

Moles?! You mean for the dirt piles, or under the house?

Are moles angry, vicious fighters? Surely you mean for the dirt piles.

[Ryan]

The fluffy dirt mounds are definitely moles. There are a few possiblities for under the house. It's unlikely but possible that you're dealing with a muskrat or marmot but more than likely it's an opossum or raccoon. We don't get badgers around here; that's eastern WA.

[Quantum]

Thanks Ryan.

Ya sure enough, I moved some of the piles, and there's a little tunnel under there, about 1.5"-2". I've read up on the mole, and found that one thing they do is dig 'runs', which are just under the surface, have a mound above its length, and tend to run along fence lines, sidewalks, etc. Well, I don't have any discernible runs, but the piles are all at one end of my yard. Rough on the lawn mower.

The mole trap, is a spring-loaded harpoon, which you're supposed to mount over a run. Yep, it skewers them. The bucket is to protect it from kidz and dogz. I don't have any runs, and it's a rent-house, but I am sure glad to know what it is. Thanks.

And the nutria students suggested opossum or raccoon, but I have never seen such energy in either of those, as I heard under the floor. I believe the raccoon squeaks, rather than growls.

I've researched the muskrat and marmot, and the muskrat is very aquatic. Unlikely candidates are the Hoary Marmot , Yellow-Bellied Marmot, Olympic Marmot, as they are gregarious and tend to live in groups. The Vancouver Island Marmot has only about 40 left.

Woodchuck (Groundhog) is a candidate, to wit: "While preferring to flee from would-be predators, the groundhog is known to viciously defend its burrow when invaded by predators such as skunks, foxes, weasels or domestic dogs. It can inflict quite a bit of damage with its two large incisors and front claws, especially when the predator is at a disadvantage inside the burrow." Although they are strong diggers, and mine didn't go to alot of trouble.

I still like Wolverine as the best fit, with the wide-set eyes, but it is rare in this area.

Wish I'd been able to dispatch it, rather than maybe some old lady being frightened and having to pay an exterminator. This is a vicious little bugger (and I'm pretty mean myself).

[Ryan]

I thought you had mentioned that you lived on a lake or near water and that your place was on stilts. That's where the muskrat came from. Both racoons and opossums growl and sound sort of like housecats when they fight. 'Possums are scarier though (witnessed first hand). I'm almost 100% you're dealing with one of the two. In any event, good luck.

[Quantum]

FYI, I've apparently eliminated the moles. Looks like there were at least three, in different parts of the yard.

I used the big firecracker smoke-making thing, called "The Giant Destroyer". I was skeptical of the baits, and the harpoon wouldn't work so well, as my tunnels went deep quickly. The Lowes horticulturist said this smoke-bomb doesn't work at all and it sucks, and indeed I could not see the fatal ingredient in it, but I doubted the baits even more.

Works. Just follow the directions!

Never figured out what the raging fighters were, but plugged all the holes in the foundation.

[psprague]

Originally Posted by Quantum

The Lowes horticulturist said this smoke-bomb doesn't work at all and it sucks, and indeed I could not see the fatal ingredient in it, but I doubted the baits even more.

He's right, the smoke bombs rarely work. They kill by producing large clouds of carbon monoxide that permiate the tunnel system. I've been fighting moles for about 15 years and went through about a case of the 'giant destroyers'. It was one of the first solutions I tried. I've also tried the bait and trapping without really any success.
What I have found to work is castor oil. I talked to an Ortho rep once about it and they said it made everything taste bad for the moles. You can get hose end sprayers but I get bottles of the pure stuff at a pharmacy and apply it with a tow behind sprayer.
I also talked with a person who tended a vinyard that was constantly battling moles. He used Coumadin, a rather nuclear option, in bait form. It kills by basically turning internal organs into soup and also is indiscriminate, so it will get rid of any racoons, feral cats, etc that are around.