Snakes

[foxychic12]

<FONT color=#cc0000>What percent of all snakes are poisonous?</FONT>

[gen2]

I don't think you can get an accurate answer to that since the populations of every species of snake would have to be measured/estimated.  Also, opinions would vary as to which ones are poisonous since there is a range of strengths and types of venom.  What effect would the venom have to have before you call it poisonous?  Do you mean lethal?  Lethal to its normal prey or lethal to humans?  Lethal to what percentage of people bitten?  For example, the European viper (adder) rarely kills human victims.