Sometimes male rats will get what is called Buck Grease on their skin. It will look orangish brown and make their skin and fur greasy. It usually happens when they are going into puberty but can actually happen at any age. My Lucky is 18 months old and I started to notice he has a patch of greasy fur on his back.
So I gave him his first bath. Some rats like water and some do not. Lucky, I wasn't too sure about since he will fish frozen corn and peas out of a tub of water with no problem but he has never jumped in the water so I wasn't sure how he was going to react.
I put a towel in the bottom of the sink so he would have something to keep from slipping on and filled the sink with about 2 inches of warm water and then took Lucky over to the sink. I put his hind legs in the water and kept one hand under his front paws and head so that I was holding him up. He only has one front paw and I didn't want him to try and walk around and dunk his head in the water. I started rubbing water on his back and he laid his head in my hand and just let me do it. He must have thought it was a wet rattie massage or something.
Most rats will try to jump out of the water, will fear poop in the water or scratch up your hands and arms trying to get out of the water if they don't want to be in it. Lucky didn't do any of those things. He did jump one time in the very beginning until I started rubbing water and soap on him and then he just laid in my hand. I took him out and wrapped him in a baby blanket and rubbed him until most of the water was gone and then let him start cleaning himself.
What really made me laugh was after I got him all clean, rinsed him off and when I went to pick him up he jumped right on my shirt, getting me all wet.
That's me in my wet shirt with him wiggling out of his blanket.