My son has been having teething symptoms for a while. Constant dribbling, bites really hard on anything he can get in his mouth and a whole range of shades of red cheeks. He can be quite grumpy and has days where he cries a lot. I don't think he has been bad enough to require teething gel. What happens? Do they suddenly start crying in a different way so you know they are in pain (like with colic - which was an awful cry.)