Rats or Squirrels in loft?

Is it definitely in the loft space. I ask this because I live in a brick built sturdy house but still sometimes the birds sound as if they are dancing in wooden clogs across the tiles! They also swing on the TV aerial making a dreadful din! In a way I hope it isn't squirrels as I've heard that they can be frightfully destructive. The baiting for rats could take a while so hopefully the pest guy will get rid of them. I have one of those sonic things that plug in but mine are all on spider setting; yuk! It does say they are bad for pet rodents though. Good luck.