transdimensional mice go with em, from what I hear, they run on a treadmill that generates heat enough to fly through an ice berg...

brrrr...

then the onboard bats use radar to signal the remote controlled mice powered entrance to open... and whooosh! they go right in... them aliens is big on mice power... small minds but big hearts! easy for em to get em to do what they want...

pretty hi-tech, if ya ask me...

:)