Yellow-bellied Marmots are curious and watchful critters, often spending long periods of time standing on their hind legs on rocks surveying the surroundings while showing off a bright, yellowish tummy, after which they were named. They seem to live lazy lives, most of which is spent sleeping or basking in the sunshine. 
Considered omnivores, Yellow-bellies get most of their energy from grasses, fruits and other plant matter but will also eat insects and even carrion.