Australian creatures finally get place to sleep (5)
I believe the answer is:
roost
'place to sleep' is the definition.
(where birds sleep)
'australian creatures finally get' is the wordplay.
'australian creatures' becomes 'roos' (kangaroos).
'finally' suggests the final letters.
The last letter of 'get' is 't'.
'roos'+'t'='ROOST'
(Other definitions for roost that I've seen before include "(Bird) settle for night" , "Bird's shelter" , "Place where birds perch or settle for sleep" , "Perch where bird sleeps" , "Temporary resting-place" .)