Non fare di una mosca un elefante.
Literally: Don’t make a mosquito into an elephant
As you might guess, this is the colourful Italian version of “Don’t make a mountain out of a molehill”. I wonder how the saying arose, since there aren’t any wild elephants in Italy (though there are of course plenty of mosquitoes!). Then again, the saying may have its roots in ancient times–the Romans often made use of African elephants in battle.