i have an idea, and it can be done two different ways.
1) if you want to use only one mole, you could move the mole to each spot where it will pop up from and place a dummy object,. go ahead and rename these so you don't lose them among other possible dummy objects. then go to the properties tab in the whack-a-mole machine and create new variable. select object, the check "make a[list]". now you can add all the dummy object into the list and name it mole spawn or something. then for your code, once the mole goes down, (for style you can turn it invisible)... move to, expressions i believe, then mole spawn, random. then you can have it move up, dance whatever you want, that way it will move to different spawn points randomly
2) basically the same idea but having a mole in each hole and using toes for your list instead of the dummy objects. than tell it to move (mole1) up, but drag in your list and choose the random mole. the only problem with this is to tell it which mole to move back down. my only thoughts on this would be to give each mole a variable and when it moves up it turn the value to 1, then have something like [for all together] if mole up value =1 - mole move down type of thing...
hope this helps. if you need me to clarify anything just let me know, or if you run into any problems