Sometimes you may have to wait for a post-brumation shed before a specimen will eat. However, most usually eat right out of brumation. The post-brumation shed--for the female--initializes the release of pheromones (perfume-like substances) to attract the males for mating, in which the snakes, namely the males, may not be interested in eating. But the females should definitely be taking something right now...? Just keep trying.