If thought is life, perhaps you could enlighten me as to what part of a bacterium is doing its thinking? Does a snail, with very few neurons to rub together, think about life as it munches along? Thinking implies problem-solving abilities, a product of higher order brains. Anyone whose horse has figured out how to open the pasture gate by itself would not doubt that horses think. I doubt that you could teach an E.coli to run a maze in search of food or to avoid antibiotics. Leave off with thinking as a criterion for life, or you will be amazed at what you see, or miss.