Do you have to squeeze the air out of Playtex bottles??

I am getting very different responses on my Google search. It feels like my baby was extra fussy when I didn't squeeze the air out. But when I do it, it's harder to do it as the amount of milk decreases. It's really hard to shove my hand up the bottle to squeeze the air out. It's come to the point where I take the top half of the bottle completely off so I can reach it soo much easier.