Insect Eaters

[Megumi05]

I haven't been getting much help anywhere else so I thought I would try to post this in the lounge. I am seeking a hardy, small, fish that will eat insect parts namely crickets. I have a semi-aquatic frog and his tank gets so littered with cricket parts. It is about 3 gallons shallow water that is filtered (so water movement aerating it) and it is unheated but typical temp is mid 70s F. My best thoughts were killifish, Bettas, and mosquito fish. My understanding is mosquito fish are used in outdoor unheated ponds to control insects (mainly larvae though) as well as algaes. Could they eat cricket legs or are they too small?