Why won't my pacman frog eat?

I have had my pacman for a couple months now and he is about 2-3 inches long. And he just dosent eat enough. He is living in a 10 gallon tank with compressed frog moss at the bottom, a water dish and a light bulb over head. The bottom of his tank stays around 70 degrees Farenheit. He will maybe eat 1 or 2 adult crickets a week. I try to offer him food every 2 days but he usually won't take it. What's wrong?