The boys' mother, 26-year-old Leiny Sarceno, is out on bail after her children, a 5-year-old and a 2-year-old, were found alone on Mothers Day.
The boys were found by police, outside of their home at the 500 block of Snowden Road.
She has told police a cousin was supposed to be watching the children while she was at work Sunday, however officers tell Action News that they doubt her story.
Upper Darby police officers responded to the scene after neighbors called 9-1-1 around 3 o'clock in the afternoon. Neighbors said they had seen the children out and about all day and not once spotted an adult with them. One of them told Action News that one of the young boys was nearly hit by a car as he roamed around the streets unsupervised.
They were locked out of the house and spoke no English.
"No human being should live like this," Upper Darby Police Superintendent Michael Chitwood told Action News. "They were living like they were in a dump.
"When the officers looked at the kids it looked like they hadn't bathed in like 2 weeks," Chitwood added. "They were filthy and they stunk, to be quite frank."
The boys were covered in insect bites and looked like they were underfed according to officials. Police got inside the house, but only found deplorable conditions. No adults were home.
"There were roaches running around on the floor, on the walls. They could actually see mice running through the house," Chitwood said of the reports from his officers who entered the home.
Police took the boys to be checked at a nearby hospital and they left a note for an adult on the door. At 9 p.m., police say, the boys' mother showed up at the police station where she was arrested and charged with child endangerment.
Police say they could not take her fingerprints or get a mug shot because she appeared to have her own medical issues.
"We couldn't process the mother because she was flea-infested," according to Chitwood.
The mother does not speak English, like her children, but through an interpreter she told police that she had been at her job cleaning a home in Paoli all day Sunday.
Police said her sons are now with other family members who live in the area.
The rowhome where the woman and her sons lived has been declared unfit for human habitation.