Liz, I am assuming you do feed your kitties!
You are witnessing bengal kitten behavior! Some bengals babies are worse than others. This is why we tell people you have to bengal proof your home. They will get into EVERYTHING and find the smallest thing you couldn't see. The key is to make sure things are put away so your babies aren't eating or chewing on something they shouldn't. They make chew toys for cats -- and hopefully, cats can't actually eat them.
Just as human parents will have a child that is into everything and all things -- it can be that way with a kitten. It should get better as he gets older. The other thing is boredom! Hopefully, your babies play a lot and you engage them in play a lot as well. They need distractions. They go searching for things because they are bored and MUST look for trouble!!!
I don't believe their adult teeth come in for several months yet, so teething is probably not the issue. Simon is bored ... so make sure he has other fun things to concentrate on. And he may need toys that are indestructible.