Need Help on the C++ code

So I’m trying to make a monster similar to the ratking, but for insects.

(background info down here, forum wouldn’t let me put in a spoiler, so just scroll down to the line)

So I downloaded code::blocks and started doing some reverse engineering/self teaching like my good old SS13 days.
Wanting to actually start the mod after halfway confident with my skill, I started looking into the ratking C++ code,
everything was going smooth, until I tried to add an the insect counterpart to the rat/ratting effect.

So I see that in monattack.cpp there is a little bit of code governing ratking’s attack.

if (rl_dist( z->pos(), g->u.pos() ) <= 10)
g->u.add_effect( effect_rat, 30);

And it talks about adding the effect when a player gets too close (I believe), but where is the actual code for effect_rat?
I mean, precisely the code that might say something like this from what I’ve gathered from the mutation code.

g->u.mutate_category( rat );

I’ve looked on github to no avail, for a moderate amount of time.

Where is the code for effect_rat kept?
How can I add my effect?

Any help would be appreciated,

Btw this is my first ever post on a forum, but I’ve been lurking for a while, so I’m not too intelligible around forum common procedure.
If I’m doing something horribly wrong, tell me! =p

player.cpp, search for effect_rat

Thanks, I found everything I needed there!
Still not sure why when you search effect_rat in the repo search on github it only turns up mondeath.cpp & monattack.cpp, but aside from that, now I dont have to waste even more of my time repo searching. =p