Reg hops about finding burrowing rodents (7)
I believe the answer is:
gophers
'rodents' is the definition.
(gopher is a kind of rodent)
'reg hops about' is the wordplay.
'about' indicates anagramming the letters.
'reg'+'hops'='reghops'
'reghops' is an anagram of 'GOPHERS'.
'finding burrowing' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for gophers that I've seen before include "Computer browsers" , "waffles" , "Creatures" .)