Is there some way possible a raccoon can get in between the walls of two townhomes?

I keep hearing mumuring sounds either in my attic or in the walls in the early hours of the morning like between 4am and 8am. It's not constant maybe every 20 minutes or so. Also I hear crackling sounds and sometimes scratching. I've had many pest control companies to come out but they can't see how something of that size get in my attic or the walls. My townhome has been treated for roof rats many of times, but I still keep hearing the same sounds.