Public health officials have been tracking a California woman for three years due to a fixation that they're concerned could sicken others.
The 43-year-old woman, only identified as Erica J., breeds rats, earning her the nickname "Rat Girl."
According to KTVU-TV, officials exterminated about 1,000 rats that had been living in her hotel room, which was her residence at the time, and infiltrated other rooms in the area in 2011.
From that time, officials tried to get Erica help.
"I was immediately concerned for the well-being of Erica. I believe that there's a serious underlying mental health issue that needs to be addressed and it seems to be unresolved," Animal Care and Control Captain Denise Bongiovanni told KTVU.
Watch KTVU's report with footage of the conditions Erica made for herself in 2011:
The issue still seems to be following in Erica's wake though. Homeless and living in San Francisco parks, the news station reported that many had spotted Erica still living with and transporting her rats.
"She had the rats living off of a cart and apparently some of them had escaped and were burrowing into an area near a pedestrian bridge," Bongiovanni said. "Our officer went out and tried to locate them and tried to collect them, but was unable to at the time."
The latest sighting was in early May when someone reported seeing eight rats eating dog food out of a bowl, according to KTVU.
The issue rats have with regard to public health is they can carry disease and parasites.
The rodents collected by officials over the years that were sick or wild were euthanized or exterminated, while those that were tame were adopted. When workers try to collect the rats, Bongiovanni told KTVU she thinks Erica hides some.
"She has come across as being very anxious and always concerned that she could keep a couple of rats," Bongiovanni said.
Rebecca Katz, head of the Animal Care and Control Department, told KTVU she doesn't think prosecuting the woman for violating the city's code would make a difference in her actions.
At this point, Bongiovanni said she thinks Erica has housing again, but she fears "this situation is probably going to continue wherever she lives until she gets the help that she needs."