Commercial tenants do not have the same rights as residential ones. The law assumes that commercial tenants are more able to negotiate the lease to protect themselves.
Commercial leases have no implied warranty of habitability, so the presence of vermin like rats is not by itself an excuse to cancel the lease. You have to rely on the language of the lease itself.
Does the lease say anything about the premise of rats or rodents? Does it say anything about being suitable for your business? Even if you don't see such a provision right away, you should have a lawyer examine it to determine whether it implicitly allows you to cancel.
Probably not. If the lease states the purpose of your business and it is clearly inconsistent with the existence of rats, your remedy is most likely having an exterminator take care of the problem. The requirement that landlord's keep the premises free of vermin only apply to residential leases.
I agree with Attorneys Eschen and Kane that you likely do not have cause to terminate the lease. Unlike residential tenants, commercial tenants are treated as savvy business people on the same footing as the Landlord and capable of negotiating a lease with terms that protect their interests. That said, there could be provisions in the lease that provide an out for you, but you would have had to negotiate them into the lease. For example, there may be a warranty from the Landlord regarding the condition of the premises or the suitability for your specific use. Unfortunately, though, such terms are not usually found in the lease presented by the Landlord so, if you (or your attorney) didn’t insert them into the Lease during negotiations, they likely are not in the agreement. If you cannot find anything in the Lease to help you, I recommend that you have an attorney review your lease agreement and apprise you of your rights and responsibilities under the agreement.
Alternatively, speak to your Landlord about the situation and find out if 1) they will pay the cost of extermination and clean-up or 2) they will negotiate a termination.
I wish you good luck.
This response does not create an attorney-client relationship and is not intended to provide legal advice for your specific situation