Night of the Lepus

Night of the Lepus, also known as Rabbits, is a 1972 American science fiction horror film based on the 1964 science fiction novel The Year of the Angry Rabbit.

Rancher Cole Hillman Rory Calhoun seeks the help of college president Elgin Clark DeForest Kelley to combat thousands of rabbits that have invaded the area after their natural predators, coyotes, were killed off. Elgin asks for the assistance of researchers Roy Stuart Whitman and Gerry Bennett Janet Leigh because they respect Coles wish to avoid using cyanide to poison the rabbits. Roy proposes using hormones to disrupt the rabbits breeding cycle and takes some rabbits for experimentation. One is injected with a new serum believed to cause birth defects. However, the Bennetts daughter Amanda Melanie Fullerton loves the injected rabbit, so she switches it with one from the control group. Amanda is then given the injected rabbit as a pet, but it soon escapes.While inspecting the rabbits old burrowing areas, Cole and the Bennets find a large, unusual animal track. Meanwhile, Coles son Jackie Chris Morrell and Amanda go to a gold mine to visit Jackies friend Billy but find him missing. Jackie finds more of the animal tracks in Billys shed, while Amanda goes into the mine and runs into an enormous rabbit with blood on its face. Screaming in terror, she runs from the mine. ........

Source: Wikipedia