There is special expanding foam that has a sour taste that is supposed to deter them chewing through it. 

Obviously that must be an exaggeration, but many of my friends are fighting them and I've heard a few stories of chewed up wires in vehicles because the rats are attracted to a certain type of wire sheathing that some auto manufacturers use.

They let it wander loose in the house and it dug or chewed the carpet under the furniture.

(To my surprise, they chewed on the baseboards when they were out of the cages which they supposedly never got out of.)I think @Scott Mac has a good point though. 

They have a one year old child so I would be a bit concerned about the child chewing on an ant trap if we left those out in the open.

Oh, and that dog the chews up the door jams!

I don't fancy myself a developer because this is more than I want to bite off and chew right now.

If the rodent finds the battery line and chews it, then it would seem that Darwin has already come up with a solution to your tenant's problem.

For sure I'll want to do in person, I learn better that way anyways.For sure stuff to chew on here.

I am with the tenant on the dog deposit, big dog small dog I don't see the difference, they pee on the floor or chew on the woodwork it doesn't matter what size they are.