"...but pest control companies are required to humanely trap and relocate them...to Virginia?"

PDQ. the law specifically exempts rats and mice...exempt...does not apply...straw horse argument.
The law is written to address problems with squirrels, chipmunks, skunk, possum, raccoon, deer, coyote, and the like.
You appear to be unaware that DC has a substantial wooded area, Rock Creek Park, running through most of the city. This is the source of enough large animals that the law was a good idea...but the law isn't about rats or mice.
It is not a law that protects rats. Rats Not Protected. Rats Not Transported. Rats not pampered. Rats KILLED. Rats Not Sent To Virginia.
Rats not mailed to Ken Cuccinelli. Rats not delivered to his mom's house. Rats Not sent to your house. Rats KILLED.
So are you clear on the basics Re:rats and this law now? If not I suggest you reread the text of the actual law. The wording is quite transparent.