2nding this. OP, if you hold a moral point against killing animals, you would be counterbalancing the mice with a cat. The Newark Humane Society almost always has cats that they rescue from the streets or from Animal Control, which is a kill shelter.

You would save the life of the cat and gain a companion - yes, it's a responsibility to care for a cat but it will kill and eat the mice since that's what cats do by nature. The smell of a cat will deter most mice in the future until you or your landlord can find and fix their ingress points.

The mice will go away as soon as they smell cats. Had a few mice in my apartment. Adopted a cat and they never came back. The cat didn’t even get a chance to hunt them.