I would for sure be telling the parents what happened and discuss ways to deal with his chewing as it isn't normal at two to need this amount of oral stimulation. Unfortunately you may have to pay for it yourself since it does come down to supervision in the sense that if child was being watched you would have stopped him before he mouthed the couch so it really isn't the parents fault so to speak. Your insurance may cover it but according to the revenue Canada rules if you can prove that something is directly damaged by a daycare child the repair is a claimable expense. Wear and tear is not so a sofa that doesn't last the full 10 years intended isn't covered but a chewed hole to be repaired would be covered. Keep all receipts and take a picture of hole to put with receipt as well as maybe send the parent an email or type up a letter outlining the situation and asking for assistance with dealing with the oral issues - that will be your proof that it was done by a daycare child.