Cuz they're shy and don't sing in public. You gotta go out to the woods and lay down and stay real quiet, not hardly breathing or anything. You gotta lay there long enough that they either get used ta ya or think yer dead, one or the other. Finally, they'll come out and play and pretty soon they'll all start to sing. Different songs at first, but pretty soon all of them will start singing the same thing, usually "Kum By Ya" or "Three hundret millyun barrels of beer on the wall" or "The Notre Dame Victory March" or some other popular song. They'll all start to laugh and then pretty soon one'll sing a song and teach it to the others and that'll go around the circle for awhile. Somebody'll break out the fermented nuts and before ya know it them squirrels will be singing stuff like "Three Whores Came Down" and "Barrett's Privateers" and next thing you know there'll be a big fight over the words to someting like "Eskimo Nell" and then the squirrel cops'll come and haul the whole bunch off to the nuthouse. Squirrels got really good singing voices, but you can't hardly git banjoes and guitars and piobrachs small enough for 'em to play, so they only sing when they feel safe among their friends.