Hi S., sorry about the late response. I think you may be dealing with SPD or a sensory processing disorder. I am not a phasision but my son has an auditory processing disorder which is a sort of spin off of SPD. These signs are showing that he may have a hard time with over stimulation. Meaning that getting excited, overwhelmed, or even just weirded out by strange textures *displaying sensitivity to foods, feeling textures in his hands and feet such as carpet, and grass,) this also contributes to oral exploration of unusual textures like crayons, sand, and paperpaste. It's not so much the taste as it is the feeling he feels in his mouth. There are theraputic items you can buy that are safe alternatives to the objects you mensioned above. Fountain valley hospital has a dept dedicated to these special needs usually physical and occupational therapies are recommended and a great help. To see more about it you can go to www.sensory-processing-disorder.com/sensory-processing-di..., this was and still is an awesome resource for me and my son. I wish you and your baby the absolute best even if this is not what he is dealing with it is a great start. Please feel free to contact me if you need to talk, I know you don't know me but if I can help in any way, please don't hesitate to ask. Again the best of luck and blessings to you and your son.