The Sonic Summoner is an optional gadget in Ratchet & Clank. It is a helmet that summons sand mice from the ground when found, which float in craft and fire bullets at enemies. The Sonic Summoner is obtained by presenting the hoverboard race prize from Blackwater City to Skid's Agent on Aridia.
The Sonic Summoner device uses a hypersonic pulse emitter to produce a sound wave at just the right frequency that attracts a sand mouse, aliens which live underground and float in a tiny craft. When wearing the helmet near a sand mouse's house, the sand mouse comes out and hovered by Ratchet's shoulder for a moderate duration of time, shooting any enemy within its range. Sand mice are found on almost every planet.
Behind the scenes
The original sand mice summoned could not fly; it would reward Ratchet with a lump sum of bolts upon meeting it and would sometimes require the player to walk it to another sand mouse house before presenting a reward.