Worldgen's "distributeprefabs"

[skittles sour]

I'm trying to get rabbits and monkeys into the overground forest, and I have something like this:

AddRoomPreInit("DeepForest", function(self)
    	local distribution = self and self.contents and self.contents.distributeprefabs
		distribution.monkeybarrel = 0.00000035, 
		distribution.cave_banana_tree = 0.0000035, 
		distribution.rabbithouse = 0.000000000015, 
end)

And what I've noticed is that even with this infinitesimal amount, I am still getting this bizarre worldgen where bunches of rabbits and monkeys are spawned alongside the roads

Does anyone know what I'm doing wrong with this and what the correct way to go about this is?

Edited April 12, 2022 by Bad Willow