Bodily fluids and their attendant odors are usually diligently purged from hotel rooms by conscientious cleaning staff and attentive management teams. Not so with these hotels. Beware!
This Tripadvisor reviewer had solid advice for other travelers upon leaving the Microtel of Philadelphia.
DO NOT stay here if you don't like sleeping in other peoples' bodily fluids accompanied by the aroma of urine.
Not all unpleasant odors necessarily come from humans. For instance, this reviewer had this to say about an innkeeper's cats:
The smell of cat urine was immediate and strong. The floors were covered in dirt, old Flyer's posters, Christmas trees half up, newspapers hoarded all over in boxes, trash on the floors. She proceeded to show us our room, upon which the cats followed right behind. The floors were filthy in there also and it looked as if it hadn't been cleaned in God know how long. Literally a pigpen.
This review of the Sheraton notes:
I noticed that there was thick yellow pee on the back of the toilet bowl - the kind that had been there for a while. Yuck.