Nah, they're gone or you have got another infestation, I've dealt with loads of them over the years and one recently in my own garage. Another sure fire way of knowing they have gone is no more droppings or damage. One of the problems with poisons or anti coagulants is the smell as they decompose, the little monsters always find the darkest corner to die in, I had one in the bottom of my washing machine one winter when i asked the council to deal with them, the smell was awful for about two weeks and we only found the body when the machine broke down and the engineer found it.
Give me traps every time.
The worst infestation I ever dealt with was in an old house I bought which had three foot thick walls and lime mortar, When i bought it the place had been unoccupied for about 6 months but everything was still in it, the mice had been living the high life on the contents of the kitchen cupboards and the walls were literally alive with them, We found a Christmas cake in one cupboard which looked as though it was untouched but all it was was an icing shell, they had eaten all the cake and the marzipan.
I baited the traps with cake and it took about two weeks to catch them all, i made sure the only food in the house was on the traps and the little buggers were starving, I found one corpse in a trap which had been half eaten by its mates.
I also cleared a shed for a mate by sealing the windows, starting his petrol mower in the shed and sealing the door. when the mower ran out of fuel all the mice were dead but you have then got the problem of getting rid of the bodies again. We ended up emptying the shed and cleaning and checking every box and bag, we would have been better off trapping them.
I could go on for pages about mousing, there was another infestation under a fish pond, the guy had used a layer of polystyrene insulation blocks under a layer of carpet and then the liner, it was mouse heaven. I cleared that one with my brother in law, his two terriers and a strimmer motor. We blocked all the holes I could find and put a tube from the exhaust from the strimmer down one of the other holes. The mice were gassed in their beds and any that escaped were snapped up by the dogs, that was a mad afternoon, the dogs loved it and we were in hysterics at their antics.