One winter at my dad's old pond I watched a single mink through a spotting scope catch and eat five small LMB in an hours time. There was patchy ice on the pond at the time, it would dive through a hole then get back on the ice and eat a LMB. The mink then spotted a muskrat on the far side of the pond up on the ice and started stalking it. The muskrat headed back into the water before the mink got close so it wasn't clear how that ended.