This quest is given by Cryptkeeper Maglus after you complete his second quest. Maglus asks you to enter the scarab hive and collect special antennae from the scarabs there.
1. Enter the lair.
2. Stand on the center circle to awaken the guardians. They are simple level 25 heroics, but you will want a group to kill them.
3. After the guardians are dead, the queen will spawn at the bottom of the stairs across from the lair's entrance She is the same as the guardians, but she has several little heroic friends with her. (These drop the antennae.)
4. Turn in the quest for experience and leggings.