a commission for  serling who wanted a rat tf and story (not his stock)

Dave was a science geek. There was no two ways around it. And when he heard of an internship at a new lab he was ecstatic when he was picked to be that intern. He got up early that day and quickly got dressed not even caring to notice what he had on and rushed right over. He got to the lab and saw one of the scientists sticking a large and unhappy rat into a cage.
“oh hello your early” he said sounding surprised.
“umm...yea I figured first day and all.....didn't want to be late” he said suddenly feeling underdressed.
“here sign this disclaimer real quick, and ill go get you a drink” the scientist said passing a clipboard to Dave. There were so many spots he need to sign that he barely finished by the time a glass of water was brought to him.
“here you go. Let me go get my boss and we'll get you started” the scientist said and left once dave had taken sip of the water. 'huh it must be the city water....' he thought. The water tasted funny, even to the point were he decided not to drink it. He waited by scooting around on the desk chair he was sitting on. He had launched himself off a wall when his stomach gurgled rather painfully. 'gee didn't thing bad water would hit me that fast' he held on to is stomach as it started to fell not just funny on the inside but the out side too. Confused hi lifted his shirt to find white fur growing all over his belly. “what the hell” he said out loud. He looked at his hand, they were looking more bony and knobbly that the had before. He tried to get off the chair but ended up getting tangled in the seat and fell. He saw the fur start to peek from under his shirt sleeves. He tried to make it up to get to the door but he seemed to be getting tangled in his ever increasing in size clothes. 'wait that not my clothes getting big....' he thought in a panic once he realized he was the one getting smaller. A small bump emerged from his tail bone area and grew long as he got smaller. He grunted in discomfort as his face pushed out to a rat muzzle and his ears rounded out and moved up his head. He tried to yell out for help but at this point all he could muster as some weird not quite rat squeaks. His body muscle moved around till he was more rat than human shaped. His eyes turned red and beady as he finished shrinking to were the wheel of the chair was huge. The now colossal door swung open with a huge gust of wind when the scientist came in and looked down at him.
“well there you are, Lets get you acquainted with your new lab partners” he said reaching to scoop dave up. . He tried to run but he was so small he couldn't cover much ground before he was flying trough the air and landed on some soft wood bedding with other rats that looked just like him.