The Museum houses certain birds (4)
I believe the answer is:
emus
'certain birds' is the definition.
'emus' can be an answer for 'birds' (emu is a kind of bird). I'm not sure about the 'certain' bit.
'the museum houses' is the wordplay.
'houses' says the answer is hidden in the clue (part of the clue houses the answer).
'EMUS' can be found hidden inside 'the museum'.
Can you help me to learn more?
(Other definitions for emus that I've seen before include "Large flightless birds of Australia" , "Running birds" , "Largest native Australian birds" , "Fast, but not high-fliers" , "Aussie birds" .)