Resistance is Futile (AKA: I’m in a bad mood)

I slept like crap last night. I overslept this morning (aka hit snooze too much). I’m going to be in the field most of tomorrow so I’m feeling behind. I feel dehydrated, probably because I didn’t drink enough water yesterday. I decided not to write a blog post this week.

Oops.

Let’s break it down.

First – Over 80% of the mice tested were resistant to bromadiolone baits. That means for every ten mice that feed on the bait, you will only knock off two. Eight other mice will go on to live happy little lives and pass their resistance to the next generation. Future generations will become even more resistant until practically nothing dies when feeding on the bait.

Next – In a choice feeding test, meaning they could choose to eat bait or something else, NONE of the resistant mice succumbed. All of the “normal” mice kicked the bucket. Reading through the materials and methods, they compared wild mice with resistant mice caught a few years ago that were being reared in a lab. Those mice that had been in the lab for several generations were completely resistant to bromadiolone. This was determined because their parents had nothing to feed on but the rodenticide and all survived. This means they knew the newly field-collected mice were similar in genetics to those lab-reared ones. Basically, the human selected resistant mice were essentially the same as the field collected resistant mice. What does that look like? Looks like this:

And – That choice feeding test means they had a choice (duh). So what if it wasn’t resistance and it was more aversion (they just didn’t eat the bait)? Great question, thanks for asking. The researchers thought of that too. So they measured how much was consumed. The resistant mice actually ate MORE than the susceptible mice! They got a bigger dosage of bromadiolone and still survived! What does that look like? Looks like this:

Finally – Even then, it took those susceptible mice about seven days to die. Bromadiolone is considered a second generation “single-feed” anticoagulant. This can be a bit weird considering that it took them seven days to die, but the poisoning may take several days to deplete their little bodies of vitamin K. Resistant strains just laughed and said “hold my beer”.  What does that look like? It looks like this:

Sure, people are going to say, “it’s the wrong house mouse,” and “it’s just one rodenticide,” and even “it’s not in OUR area!” Doesn’t matter. It’s emblematic of an ongoing and worsening problem everywhere. Rodenticides are not being rotated. We are creating resistance. Rodent control programs are outdated and quickly becoming ineffective.

I’m going to go drink some water and get some meds for this blooming headache. You are going to contact me to update your rodent SOPs and training so you can outcompete your rivals with better service and better results. Do it now.