Everybody's a snake, that's why I try to keep the grass cut
See it when they coming, then I heat they ass up

from Flatbush Zombies – Regular and Complex (GNB) Lyrics on Rap Genius

Meaning

These lines are taken from The LOX song “Fuck You” including a sample of Jadakiss‘ verse at the very end.

http://www.youtube.com/watch?v=pGx8Kw1jUxA

In normal context, the line depicts a sense of untrust against most with their own devious intentions and plans to screw someone over. It becomes a metaphor for keeping your your grass cut or being aware of your surroundings to spot the snakes in the grass, disposing of them as soon as they’re noticed.

To help improve the meaning of these lyrics, visit “Regular and Complex (GNB)” by Flatbush Zombies Lyrics and leave a comment on the lyrics box