For frogs: 30 min per frog, 10 joules per frog=20 joules per hour. For crickets: 12 minutes per cricket, 2 joules per cricket=10 joules per hour. The raccoon should forage in the stream.
Work Step by Step
This is a simple matter of calculating from the data given; work to get the energy yield per hour to see that the stream is a better place to hunt.