The idea of rats with fleas makes me want to curl into the fetal position.
I saw a picture of something once called Rat King and I was honestly on edge for days.
Story time:
When I was about 8 or so, there was a weird scratching behind my bed at night. I told my mom, and she assumed it was probably a mouse or something (it was a pretty rural area). Later on, I discovered, there was a hole the size of a fist behind my bed, my mom freaked and got it closed up asap. She told me a few years later that not longer after that she saw a giant rat (she said it was chihuahua size, but who knows) in our garage. Thus the dislike and fear of rats began.