You need to be work with the layers panel open (and show it here to get the best advice) and have the little incons shaped > clicked open so they change to v to see the contents if you have the 2 objects on different layers you may need to change the layer order to move one thing behind another or you might be just sending the rattle to the back of it's own layer, but that whole layer is still be in front of the layer the bottle is on. if that makes sense. To get better help with this project you could save the .Ai file and upload it to a file sharing site eg Dropbox, Google Drive, Adobe CC, etc and provide the sharing link here then someone can open the file and better advise you
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