Strolling Amok

Refitting for Battle

Am I not merciful?

Sometimes, life is simplified down to its basic components. In order for one thing to live, something else must die. Sometimes, in order for one thing to be able to sleep, something else must die. I’m the one thing. Mice are the something else. That’s the way I prefer it, anyway.

Rodent infestations aren’t talked about much on RVing blogs, because it’s mundane and reduces the glamour of the lifestyle. Seldom do you read, “We saw the magnificent Grand Canyon today! But we were all so tired from a couple of sleepless nights from all the mice in the trailer that we were too tired to really enjoy it. Merla’s concerned we’re going to catch that Hantavirus if we can’t get rid of them.”

Once inside, mice are quite noisy at night, and basically treat the Defiant as their playground as they search for stray food remnants. Plus, they poop and pee all over creation. Chewing on everything, running along or inside metal enclosures or ductwork, or just doing sprints up and down the kitchen linoleum, they easily wake me even from a sound sleep. Then I wonder, “What are they destroying now?” In the ancient days, when I was short of sleep, I felt a bit tired and sleepy during the day. Round about now, any meaningful lack of sleep feels like death warmed over. This means war!

In the last year and a half, I’ve had three such mouse infestations. To make it more fun, I’ll call them hull breaches. Each of them occurred on remote campsites with at least sporadic ground cover on National Forest land. Each of them started at about the two-week mark, as if signaling me that it was time to move on. One mouse somehow finds a way in (which remains a mystery to me as to how) and soon brings his buddies. Three nights later, it’s Party Central.

To this point, the only real solution has been to move the trailer. I’ve set live traps and snap traps inside. And outside, buckets of water with ramps leading to bait on the handles. (The handle with peanut butter on it rotates with the mouse’s weight, and he falls into the water.) Fortunately, these mice are largely unacquainted with the dealings of man, and are caught more easily than their residential counterparts. But, the catch rate is never 100%, and the problem never goes completely away. The remaining ones become more elusive. Infestations seem more preventable than they are stoppable, once rolling.

Since I just recently had to tie down the solar panels and relocate the Defiant a half mile up Old 89 (NF 9711F) to another (nicer) campsite I found, I decided that it had become necessary to develop and deploy a Rodent Countermeasures System (RCS). Since I cannot quite afford the automatic heat-seeking laser guns that you see in movies such as The Andromeda Strain, my system would have to discourage initial entry and then step up the aggression on any breaches of the Defiant’s Defensive Perimeter (DP). The RCS enforces the DP, don’t you see. So, mice can’t take a pee on my tea.

So, I organized a Rodent Countermeasures Task Force (RCTF) to study the situation and make recommendations. Not surprisingly, I quickly found that forming a task force is remarkably easy when you live alone, and getting a consensus is a slam-dunk – as long as you’re not by nature indecisive.

Reviewing the options, defensive measures need to begin outside. An external lure trap such as a baited water-filled bucket has to be placed in proximity to the trailer in order to draw attention away from it. The good news is that it draws mice already near the trailer, hopefully proving more attractive than the trailer itself. The bad news is that it attracts mice in general, and attracts them toward the trailer’s general vicinity. Placed some distance away, it eventually stops drawing a rodent’s interest away from the trailer. But, mice are social critters and do not travel very far when scrounging for food, so the size of the group being lured in is limited, at least for the short term. If an external lure trap is used, it needs to be placed close enough to compete with the trailer.

But, it would be best if it weren’t needed at all. Using a lure trap outside is like sending a radio signal out to the Borg Collective that you’re near the source of the signal. Not the best first choice if you’re not assured of utterly wiping them out on the first go. That happens neither with the Borg, nor with mice.

If anything, what I need is a way to discourage interest in the trailer outside and inside, and then to intercept any more persistent critters with lethal countermeasures inside. This would mainly be to prevent their announcing to their homies where the party is.

Ultrasonic devices to repel rodents get mixed reviews, most likely because

A) The manufacturers don’t stress that ultrasonic devices have basic limitations. In the struggle to differentiate their product from all the rest, they at best mince words when it comes to no-win situations. At worst, they ignore them.

B) Many customers, rightly or wrongly, expect to hit the on switch and watch mice run for their lives. Then they’re incensed when they watch a mouse stroll past and gesture rudely.

In truth, ultrasonic devices are merely a mild repellant to rodents. They’re like your kid cranking his favorite “Screaming Toads” CD up to 100 decibels. It doesn’t keep you out of his room and doing what you need to do, but unless there’s some compelling reason for you to be there, you will prefer not to be. Likewise, if mice don’t quickly find a compelling reason to be in your trailer, they will tend to go where it is less unpleasant. Ultrasonic devices are useless against existing infestations, and against food being left available and readily accessible. If mice have already staked out the joint, adding sound won’t alter the situation. In an initial encounter with no perceived reward however, ultrasonics tend to be persuasive.

An ultrasonic speaker. Tiny, ain’t it? The same brand offers much bigger multispeaker units for 6x the cost, but the decibel level isn’t any higher. They are for aiming issues.

So to my way of thinking (however you may choose to define that), the last thing I want is for a mouse to find his way in, encounter food, and head back home to report the new neighborhood food source. That’s what’s been happening, with snap traps and lure buckets being deployed after the fact – after it’s too late. That results in a pitched battle with no end. An 80% attrition rate is not a win, nor is it an assurance of a good night’s sleep.

A good Rodent Countermeasures System makes a mouse’s life inside the trailer unpleasant enough that, without an immediate edibles reward, they will be motivated to wander back out. Better yet, if they have committed to stay inside, they shouldn’t remain able to wander back out. Should they persist in searching, the first thing they should encounter is a baited snap trap. Or two. This does not guarantee a 0% chance of his reporting back home, but it’s much better than simply waiting for evidence that mice have visited overnight, as I have been.

The optimal RCS is proactive, and in operation overnight, every night – at least outside of areas already known to be rodent-free. It consists of an ultrasonic speaker under the trailer, to try to dissuade a mouse from spending a lot of time searching for that magical path up and in. (I’ve been under the trailer on a crawler, looking for it. No soap.) Another speaker suitably located inside the office and another in the main living area should be sonic overkill for the square footage, making the trailer interior unpleasant.

With the entry point unknown, figuring out where to intercept with snap traps becomes more problematic. The narrow passage from the office to the living area makes for a logical start, with another being both sides of the kitchen runway. The mice seem to spend most of their time along the edges of open passageways, rather than squeezing through tight alternates. But, once established, they’ve also spent time inside the lower kitchen cabinets and the furnace, of all things. Four snap traps ought to do it, and there are permanent locations available that aren’t in harm’s way. Food is sealed away, obviously, but not everything edible to a mouse can be. By the way, baits of peanut butter or peanuts work okay and are more of a draw than cheese. The lure they go crazy for has been olive oil though, believe it or not.

The caveats of this type of system are several. Each Victor “Mini Sonic Pestchaser” speaker chews up 2 watts on 110V AC power. Considering the Defiant’s battery pack capacities, that ain’t much, but the need for alternating current power means that inverters must be used, and they absorb power themselves, about 5 watts or less at idle. The interior pair of speakers is powered by the living room inverter, which coincidentally also powers my night light. That inverter runs off of the house batteries. Throw the inverter’s switch on in the evening, and the interior system is operating.

The speaker unit broadcasting under the trailer is more problematic, at least until a more permanent approach is sorted out. For now, as an improvised setup, it consists simply of a cigar lighter socket clipped to the terminals of one of the house batteries. Into that socket is plugged my pre-existing cheapie little 50-watt inverter. Into the inverter is plugged an ultrasonic speaker. I have to remember to attach one of the squeeze-type battery clips in the evening to turn on the speaker, and unclip it in the morning. Or just leave it clipped. Until I move.

With 200+ amp-hours available from that pack, worrying about this load on a largely unused pack may be needless. Rainfall and travel in wet weather will be a different matter entirely. The external system needs to be housed and tucked up where it will be partially shielded by the trailer’s frame and forward crossmember. A solar-controlled on-off switch would be nice, but finding a 12V DC version could be a challenge.

The speakers do make audible noise, sounding much like the hum of a fluorescent light going bad. It’s not loud, but it’s more than barely perceptible. Fortunately, I don’t find it deeply annoying, and I’ve also got the CPAP’s white noise going to partially mask it. There is no point in running the system during the day, as mice are nocturnal.

So my system is oriented toward discouraging initial contact and infestation, not bayonetted hand-to-hand combat in the trenches. I’m effectively dropping “Nothing to see here. Move along, move along” leaflets outside, and then laying punji-stick traps for stragglers inside the perimeter. It should work, and this is the safest approach as far as sanitation goes. If it doesn’t succeed, on those odd occasions? What if it’s apparent that an infestation has begun, and that the defenses have been breached? Engage the self-destruct device?

No. Time for Old Tech. The lure bucket will be deployed outside, but in a more effective and stowable form: the Victor Tin Cat, a flattish galvanized steel rectangle with a one-way entrance. With bait inside, mice can enter but cannot leave. It’s at least conceivable that it could reverse the tide of the battle, for a time. But it’s unlikely to end it. I’ll probably still have to move, but as with the mods to the Tankmin fresh and wastewater system in the truck, only practical use over time will tell.

The Victor Tin Cat. Designed for placement along a wall, it’ll go outside should the ultrasound setup fail.

Feel free to add your own colorful and disgusting experiences as a comment.