Is it normal that i fantasise about being a lab rat?

Medical schools need experimental subjects like you. Get paid to receive the abuse you crave.

"Gee, Brain. What are we going to do tonight?"

"The same thing we do every night, Pinky. Try to take over the world."

I suspect this question is a guise by a dangerous sociopath.

There's a medical fetish that is sometimes combined in regards with BDSM. You should look into that.

I hope you know that during World War 2, both Nazi Germany and Imperial Japan conducted scientific experimentation (aka torture) on human subjects (usually captives or people whom they regarded as inferior). This included vivisection (operating on people without using anesthesia), exposing them to extreme temperatures, and administering poisons and harmful chemicals.

I advise you to browse these links for further information:
http://en.wikipedia.org/wiki/Nazi_human_experimentation
http://en.wikipedia.org/wiki/Unit_731

There's a poster in my lab's lunch area with an eight legged rat holding up a sign in protest that says "No more experiments". Suddenly I began to sympathize with the rats...

Unless of course they're doing experiment on us too like they say in Hitchhiker's Guide to the Galaxy.

That's a little strange