No a snake will not eat bird seed. The best thing to feed a snake is mice, depending on the size depends on what type, pinkies are the smallest, then there are fuzzies which are bigger. And it keeps going up, you should feed them according to their size nothing bigger than the thickest part of their body
Don't understand the question, will they eat birds? Yes they will eat anything alive, or that they believe to be alive, or recently alive, that they can get their mouths around. They will not however eat bird seed, they are strictly a meat eater.