It could be. Is he wild caught? What's the temperature and humidity in the tank? I wouldn't assume he was trying to hibernate unless he's been there a couple of days or more. Sometimes toads just like burrowing, or the tank might be too cold or not humid enough.

I wouldn't try to induce hibernation, because frogs can live full lives without doing it. In the wild frogs sometimes die during hibernation and even when it's done by experts it's a little risky.