Reptile sees everyone starting to infest Georgia and Rocky Hill (9)
I believe the answer is:
alligator
'reptile' is the definition.
(alligator is a kind of reptile)
'everyone starting to infest georgia and rocky hill' is the wordplay.
'everyone' becomes 'all' (all people).
'starting to' says to take the initial letters.
'georgia' becomes 'ga'.
'and' means one lot of letters go next to another.
'rocky hill' becomes 'tor' (I've seen this before).
The initial letter of 'infest' is 'i'.
'all'+'i'+'ga'+'tor'='ALLIGATOR'
'sees' acts as a link.
(Other definitions for alligator that I've seen before include "predator" , "one bites voraciously?" , "Fierce reptile" , "Croc's close relative" , "Vicious attacker" .)