Nikon D3100 or Canon EOS Rebel T2i?

I want to get a camera with a lot of mp and can take good pictures in low light. And one that has good AF servo. I am new at photography so I need one that is not too complicated but can take really good pictures. Also, I want one that can take pictures up close,like of a butterfly's head for example. Both can take pictures up close but I want the one that can do it the best and clearest. Also I want one that can zoom in really well. Please DON'T give me other camera ideas because these too fit in my budget and look really good, I just can't decide which one. Thanks!!!