Getting you in contact with someone to kill an annoying, cheating or robbing rat is not illegal. I do it for justice.
Since you wanted to get technical with words:
http://dictionary.reference.com/browse/rat2. a person who deserts his or her friends or associates, esp in time of trouble
3. a worker who works during a strike; blackleg; scab
4. chiefly ( US ) an informer; stool pigeon
5. a despicable person
6. smell a rat to detect something suspicious
Most modern uses of the word refer to the concept of a person just as Rwandans used the word 'cockroach' during the mass extermination of tutsis and moderate hutu people in 1994.
So you might have wanted to pick a better cop-out word & explain it to the judge.
In your context it can only be intepreted as a human being, how many people have been robbed (def. stolen by the use of coercion and violence) by a rodent?