So get them before they do. Harpoons or something. Those are simple tech, you should be able to do it.

[ well, if they have the materials to put into a simple machine. depending on how much metal they had to spare, it might not be enough for the mechanics.

god, this is freaking weird. he's talking to some guy from another ruined earth, about how to trap and kill giant cannibals. ]

So this is normal? You being from an Earth that's totally different from my Earth?

[ someone needs to stop calling things Earth, it's getting really unoriginal. and confusing. ]