Tenant brought rats from his previous residence?

[Peter Morgan]

One of my rental units never had rats. I used to live in the unit before I rented it out to the current tenant who has been living in the unit for little over an year.While vetting this tenant

I found this tenant works in a niche sector and felt he would be a great long term tenant so ok I offered him a below market rent the first year.For the second year when I raised the rent by offering him a lease, he came back the very next day with couple of things he said he is looking for another job out of state and his tenancy will be contingent upon him not getting an offer out of state so he will prefer month to month until he gets do form of a confirmation, so far so good but what startled me the most was he mentioned that there are mice in the apartment and I was in utter disbelief and asked him if he has actually seen them? and they spilled the beans rather accidentally that they had rat infestation in their previous house and they are very well aware how it "looks". Could it be possible the tenant accidentally brought rats from his previous residence when he moved to my apartment?