Mice in the house

Other

My tenants have been in the property 6 months. Recently they asked if they could keep a rabbit.
I agreed.
When I did the last inspection recently there were 2 rabbits living in a large cage in the kitchen! There was no smell, they were clean and looked after.
The tenant mentioned at the end of my visit that they had heard mice scratching in the loft area & they had been in the kitchen.
They had put a few traps down but seemed to think there was more I should do.
I bought them 4 more traps and bait. I wrote an email urging them to do all they could to solve the problem. I mentioned putting their food into safe containers.
I said if they could find where the mice were entering and I could have the holes blocked, then I would do so. I also pointed out that the rabbit food could be a source of attraction.
I don't know what more I can do. I am loathe to have a pest controller who will only do what I have suggested & charge the earth.
The mid-terrace property (about 20 yrs old) has never had problems in the past. I believe the rabbits may not be conducive to the situation.
Is the landlord solely responsible? I do not like the thought of vermin in the property or that they may chew wiring & foul the insulation in the loft. Any advice please?