They use logs to multiply snakes! (6)
I believe the answer is:
adders
'snakes' is the definition.
(adder is a kind of snake)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for adders that I've seen before include "Dreads (anag) -- snakes" , "Re Dad's snakes" , "Totting snakes" , "Mathematical snakes" , "Totting 25 down?" .)