Here another safety layer of your immune system comes in. The cute butts of Antibodies that are for friends are in a sort of “hidden mode” when Antibodies just float around, so immune cells can’t just pick them up from fluids. As soon as an Antibody has grabbed a victim with its tiny pincers, its butt changes its shape and is now able to bind to immune cells. This is pretty important since your body is teeming with antibodies at any time, and it would cause all sorts of chaos if your immune cells would bind to the antibody-butts just randomly.
