trap question

Raisford sets up a few traps to hinder his capture. There is the "Maylay man catcher", "the Burmese tiger pit" ( I love these names!), and some other tree spring thing. I think the tiger pit is a big hole with spikes in it. The Man catcher has a trigger where the man steps on and is scooped up and killed.The tree spike involved tying his knife to a sapling. Rainsford ties the sapling back with some vine. When it is triggered, it hits and kills poor Ivan, Zaroff’s "deaf and dumb" servant.