Two eggs, one taken by terrible vermin - it eats everything (8)
I believe the answer is:
omnivore
'it eats everything' is the definition.
The definition suggests a singular noun which matches the answer.
'two eggs one taken by terrible vermin' is the wordplay.
'two eggs' means two replacements for 'egg'.
'egg' becomes 'o' (an 'o' resembles an egg).
'egg' becomes 'o' (an 'o' resembles an egg).
'one taken by' is an insertion indicator.
'terrible' indicates anagramming the letters.
'vermin' is an anagram of 'mnivre'.
'o' put within 'mnivre' is 'mnivore'.
'o'+'mnivore'='OMNIVORE'
Can you help me to learn more?
(Other definitions for omnivore that I've seen before include "unfussy diner" , "I'll take in anything" , "Eater of all things" , "One fancies most things" , "One eats everything" .)