Director Mohammad N. Akhter of the District of Columbia's Department of Health told the Washington Post that inspectors have seen the rodents running around at both protest camps.
In addition, numerous new burrows and nests have been found under the hay-stuffed pallets that occupiers are using for beds.
Both campsites had working kitchens operating until last week when health inspectors pointed out unsanitary conditions at the McPherson Square site.
"I am very supportive of their rights and ability to demonstrate but I have concerns about their personal safety," Akhter said.
He said he has ordered a citywide review of conditions at the camps.
The National Park Service has official jurisdiction over the two camps and will make the final decision about whether to evict protesters.