i am not sure that aliens exist
The universe at large as much and just comes across interesting and puff in the open, and that if there is clear evidence of the existence of still other intelligent beings, it does not mean that they are not really.
It's a little bit scary to think that we're alone in this whole universe, isn't it? We're so small in such a big, infinite Universe. Nobody actually knows whether aliens exist or not, but if it really is infinite.... Then there are basically an infinity of possibilities around us. They should then exist somewhere, maybe aliens are smaller than we even imagine them to be.