Or it could be all the bats are out of range--they might be scattered all along the column to provide short-range warning, and with 22 move they wouldn't be able to reach.

Anyway, Parson's boops are really in the vice now. Given how annoyed Tool was at losing just three dwagons, losing 22 would result in instant disbanding for Parson. He really IS relying on Wanda's suggestion spell to get them out of trouble!