help!!funny noise!

ok… im just wonderin what this noise is …
it only happens on cold starts… or when i havent started it in a while …but for a few seconds when i turn it on… it makes these squeal kind of sounds… not really loud … but noticeable… the stop after about 3 seconds … then it doesnt make any other noises after that??? belts?? any ideas??
thx guys

One of the belts slipping.

Yes what he said

Mine made a squeaking noise only when I went past 3000rpm then suddenly one day it just went away without evening fixin it