maybe its "snot"? :s (a rich person has a handkerchief, he wears it in pocket a poor man doesnt use it and children usually put their finger into mouth after "cleaning" their nose with it) :)) PS. and i know another variant of the riddle like this one, but the answer is also the other: the rich man needs it the poor man has it if you eat it, you will die...

hmmm, probably fingers?

snot))))

nozzle?? we say козюльки))))))))

so disgusting!