Dani Moore suffers from spinal nerve damage. She gets muscle spasms and needs to take medication. Because of the nerve damage, she doesn't feel the spasms.
That's where the trained rat comes in. He does feel the spasms and warns Moore by licking her neck.
"He alerts me to spasms in my neck and shoulders. I have nerve injuries so I don't feel them until they get really bad," said Moore.
The /*Americans with Disabilities Act*/ has a section on service animals. It's mostly about seeing-eye dogs.
The city of Hesperia recognized Moore's situation and passed a special ordinance granting her pet rat all the privileges of seeing-eye dogs.