Yes the best way to describe it is a bellow or deep growl, almost echoing. Here is a link to an alligator growl, http://www.YouTube.com/watch?v=l3rzkrm98J0&feature=fvwrel.
They don't exactly roar - it's more of a bellow. But they can make a very loud noise.
Alligators don't speak.
Over sound waves
they hit each other
no
Crocodiles are reptilians. Piranhas are fish. They aren't close to each other.
they hit each others tail
they would likely fight for mating rights during the mating season. or they could fight each other for food.
Of course, mice can talk to each other.
A few people each year are killed by crocodiles. Many animals are killed by crocodiles each year.
Because the people that talk about other people like them
white sided dolphines talk to each other by clicking
yes bacteria can talk to each other
American crocodiles have been known to eat other American crocodiles on occasions. Other than that, crocodiles almost has no predators except for humans.
crocodiles make splashes in the water to communicate with each other.