A little Nervous

I'm getting a little nervous.  My son has a natural tendency to hoard. When he was younger he would hoard and hid food and drinks, he wasn't happy at the table without three cups of liquid at dinner.  This was alarming to me, because those are things children who are extremely abused do.  He was not abused so I wonder why he was doing such things.  I don't know, he sort of grew out of it, and we all have our own ticks right?  He likes to hoard, but my husband and I through different methods try to discourage such actions.  Until lately, I don't know whats going on he is starting to hoard again. Not just collect, collect I can almost handle. But hoard?  The other day at Discovery Gateway, he gathered every single plastic egg in the entire center then held on to them for about an hour.  No one was allow to touch them, at the sake of not playing with anything else, he just walked around looking holding on to his eggs.  Then later he hoard clear plastic balls.  When I said now what are you going to do, he sat down next to me and watch other kids play as he held tightly on to the clear plastic balls.  Then today he was gathering up material (unsewn baby blankets) and little stuff animals and in fear someone would take them, he just keep shoving them under himself.   I'm a little concerned his preschool teacher is going to tell me he doesn't play with other kids he just collects toys. I really am worried.