Whenever my dog sees a dead worm on the sidewalk, he wants to rub himself all over it.

I found tapeworm infection in my dogs fecal matter. I treated her with Droncit. My question is, once the worming medicine starts to work, where do the dead worms/worm segments go? Will it come out in her poop or what?
Also, are there any preventive steps at home I should be taking to avoid my 2nd dog getting tapeworm? Can they still play together, etc? My 2nd dog has no signs or symptoms and has normal fecal matter.
Knowledgeble answers only please! Thanks