Scientists began to investigate these possible chemical effects after seeing a colony of toads abandon its pond in L'Aquila, Italy, in 2009 several days before an earthquake, the BBC reported Thursday.
Researchers led by Friedemann Freund from NASA and Rachel Grant from Britain's Open University found animals that live in or near groundwater proved highly sensitive to any changes in its chemistry.
Such sensitivity and subsequent behavior might give clues to signs of an imminent earthquake, they said.
Scientists have been studying the chemical changes that occur when rocks are under extreme stress.
"When you think of all of the many things that are happening to these rocks, it would be weird if the animals weren't affected in some way," Rachel Grant of the Open University said.