Rodent issues after purchasing a duplex

[Koob Moua]

I just purchased a duplex in july and a tenant is saying that there are rat droppings being found now. The tenant was already there in place when we bought. Her lease contract states the landlord is responsible for termite and rodent control. But there is a box checked under that and states Landlord shall not provide pest control services to premises and is the responisiblity of tenant to keep it pest free. The lease is kind of weird because it states the landlord is responsible for termite and rodent, but the other box states Landlord shall not provide pest control services. And pests is that gereralized as all pests?

This was the previous management company that stated this in there lease agreement.

My question is can I still charge her since she is the one living there? What would you guys do?