Good morning!

I look after a 4.5 year old boy who has started sucking all his food, he holds it between his fingers and sucks on it till he either eventually eats it or it gets too mushy and gross to eat....this has started over the last month or so. At first he would suck on softer things like cheese, dry cereal or bread, now it's moving onto most everything. I've asked him if his teeth or jaw hurt, he says no. I ask him why he sucks his food and he just shrugs. It's strange and also gross because his partially disintegrated food gets left on his plate. He is an extremely picky eater, so I'm wondering if this is his latest strategy to avoid eating anything but what HE considers acceptable......anyo ne encounter this before?