Like a mole, for example, eating his grub? (13)
I believe the answer is:
insectivorous
'eating his grub?' is the definition.
'insectivorous' can be an answer for 'eating' (thesaurus). I am not sure about the 'his grub?' bit.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for insectivorous that I've seen before include "Like, eg, anteaters" , "Eating bugs" , "Enjoying, for example, cricket" , "Having a diet of ants etc" .)