In this instructable I'll show you a simple trick for killing cockroaches and ants and possibly even help plants.
It implies baking soda and fine sugar. And it's totally bio.

Please read on...

Step 1: Ingredients

First take some sugar and some baking soda.
Then mix them in a container.
There should be a ratio of 1/3 (3 units of sugar for 1 unit of baking soda).

Step 2: Pack It Up

Now take the mixed powder and pour it on a piece of absorbent paper, tissue or just about any kind of paper and fold the paper in any shape you like.
I personally prefer to fold it into a triangle for ease of storage and simplicity (as a bonus you can take it, rip it open, throw it on the ground and let it do its magic).

Step 3: Why and How It Works

Cockroaches and ants totally like sugar, but when they eat the sugar combined with baking soda, the sodium bicarbonate reacts with the water in the bugs and produces carbon dioxide gas, which bursts open the exoskeleton of the bug.(In simple terms killing the bug) DISCLAIMER ; I DO NOT HAVE ANY SOLID PROOF THAT THIS TECHNIQUE WORKS.

Also baking soda can neutralize acid soil making it fit for plants, and the sugar can help the plant grow (only if added in very small quantities). But beware it is not necessarily beneficial for the soil or plants for it can kill the microbes maintaining the soil rich for plants.

And its biodegradable.

I hope you'll find this trick useful in your battle against bugs.

PS.This is my second instructable. Feedback appreciated.