Source : Webster's Revised Unabridged Dictionary (1913)

Tumbledung \Tum"ble*dung`\, n. (Zo["o]l.)
   Any one of numerous species of scaraboid beetles belonging to
   {Scarab[ae]us}, {Copris}, {Phan[ae]us}, and allied genera.
   The female lays her eggs in a globular mass of dung which she
   rolls by means of her hind legs to a burrow excavated in the
   earth in which she buries it.