I had a mouse living in mine several years ago and that was in my daily driver! I almost wrecked when I saw it running around in the floor pan, I just the damn thing was gonna run up my pant leg, luckily it didn't. I set up 2 of the old fashioned snap traps and baited it with cheese, one in the front floor pan and one in the cargo area. The next day the cheese was gone. Great. I put more cheese on and finally caught the little sucker. That's what I would do if I were you. That way you'll know you caught it. If you put out poison, it's liable to die still in the Jeep and you may not be able to find it, only smell it! Yuck!