Lobster's can't scream, no vocal cords. And they don't "feel" pain like other animals (nor do fish), because their brain and nervous system is different.
As a note- They're nasty anyways, they are bottom feeders and eat the refuse of other animals (aka fish poop) and dead matter that has fallen to the bottom of the ocean. If their diet is poop, then poop is what makes them meaty. Yuck! I would never put something so polluted and toxic in my body.
And to the person who made a nasty comment about vegetarians- I have been a vegetarian for 11 years. I could care less that you (or anyone else) eats meat, or that you like that lobsters are boiled alive. If that's what makes you happy, go for it. Your body, your choice what to put in it. But I expect respect back for my choice not to.
Vegetarian for 11 years