Sounds on the ice

[cruiser1234]

Was on 9 inches of ice today. Kept hearing sounds like cracking an some echoing. I know the ice expands an it makes sounds but I'm fairly new so any info on those sounds or anyothers I can expect would be great. Also on the 9 inches I heard the sounds and saw more then one crack actually form right where I was standing and a few others very close by. The cracks looked to only go three or so inches. That normal too? Any info on that sort of stuff would be great. And I'd love to catch some yellow perch. I'm not asking for anyone's spot but how do I best increase my odds for them or any other species on the ice? Are spots near docks or structure, branches,trees etc good for anything. Asking a lot here. Had a good time out there!