No, Not Big Head Todd

Here in my bathroom I should expect strange odors, except that I'm taking a shower, and not pooping. What the hell is that very strange aroma?  I've cleaned the toilet, scrubbed it, and squirted that blue cleaner up under the lip of the bowl and scrubbed that. I've scrubbed the floor, twice, even under the vanity which was a very tight squeeze. I took the rubber bath mat outside and squirted it with Chlorox cleaner, rinsed it, and let it dry in the sun. I have scrubbed every surface of that bathroom, yet still it stinks.

Here is my theory. Last week the exterminator came by. I pointed out to him that we had an ant problem, and could he take care of it.
"Sure, you have ghost ants in this bathroom."
He was talking about Mark's bathroom, and I am pretty sure there are a lot of ghosts in that place. Alex the exterminator sprayed his poison all around Mark's bathroom, and then went outside and sprayed around the bathroom window.
"Okay, now check out my bathroom. I have ants crawling all over the bathtub, and under the vanity."
Five seconds in and Alex announces, "You have big head ants in here."
I must have looked at him funny because he repeated it.
"Yes, you have big head ants, that's what they call them." He was saying this as he sprayed more poison all over my bathroom. "Look at 'em go sir."
Sure enough, hundreds of ants started swarming out of every crevice. It looked like a science fiction movie, and was horrifying. So back to my theory, and that is that there is a giant ants nest somewhere behind a wall or under something in that bathroom, and the poison killed them all. I just can't get rid of that vision in my mind of millions of dead ants rotting away somewhere in my house. Can't get rid of the smell either.