I agree with Debra that he's trying get rid of the insect and not having any easy time of it. Great shot, Yves, with terrific detail throughout the image!
In this image it almost looks the frog is trying to get rid of the insect with his front leg. The lily pads ads so much interest and texture to the shot. Very cool Yves.
You may be right Debra. The too big insect may not need to escape, the frog may be rejecting the insect that can't be swallowed.