AnotherFairportfan wrote:What is this thing?
Being an actual bug in the taxonomic meaning and not just in the colloquial meaning, it has a mouth that is sort of like a hypodermic needle. So even though it is probably a plant-eating bug, one that size might still be able to give you a nasty bite if you mess around with it. So be careful if you feel like picking it up and taking a closer look at it.
shadowinthelight wrote:Perhaps the type of alcohol matters, not just the concentration?
The rubbing alcohol is isopropyl alcohol in water, the drinking stuff is ethanol in water. Different molecular formulas. Ethanol is a small molecule that mixes easier and more fluidly into water. They also break down in the body into different things that have different effects on the drinker; in humans, isopropyl breaks down into acetone while ethanol breaks down into acetaldehyde. I have no idea if ticks have the same metabolic pathways, but they still probably break the two alcohols down into two different types of chemicals.
Ticks don't actively breathe the way that we do. They just have some small openings (spiracles) in the back part of their body that lead into tubes (tracheae). The tubes lead into smaller tubes, and those wind their way through the body. There are no lungs, there's no controlled pumping of air. They just have the air randomly flow through their bodies. Being tiny little critters with slow metabolisms, they also don't need to breathe all that much.
With all of that considered, I think I can see why rubbing alcohol would be less effective than good ol' booze. The smaller size and lower viscosity of the ethanol might let the alcohol flow into the spiracles more easily, so more ethanol gets into the tick. Also, acetaldehyde is much more toxic than is acetone in humans, and could be the same in ticks. So you're getting more of the alcohol into the tick, and the alcohol is made into more toxic stuff.
Or the ticks just can't hold their liquor very well.