Rats

At Brookdale Institute, where the wealthy go for rehab, something lurks behind the walls. Years ago, they conducted experiments on lab rats. The scientists have moved on...but the rats remain and have mutated and multiplied. Now, the genetically altered beasts are out for blood and have a taste for human flesh. With the clinic's patients locked inside, it's only a matter of time before the rats find their way in for their next meal. (official distributor synopsis)