Watch the pythons' tongues go in and out. That's called tongue flicking. This is a snake's way of smelling. Watch, also, the pythons' eyes. See if you can out stare it.
Snakes never blink.
They don't have eye lids. Snakes don't eat very often, you might be surprised to know. In the wild snakes feed very infrequently. And these Burmese Pythons are only fed a couple of times a month. A full-grown python could actually go a whole year without eating.