Making Ladybug Antenna for a Cake?

No, but if it's 2 dimensional (flat cake) It would be cute to use lollipops (could be dipped in candy melts to match cake) to stick up out of the cake. Would actually work for 3 dimensional, as well.

Oh, I hadn't thought of dipping lollipops in candy melts. That's a good idea, thanks!!

I would use black licorice. You could cut it thin enough, just for the antennas.
I use it for hair, eye lashes, etc., for all my cakes and cupcakes.

Black licorice whips?

Try using the jellied string candy or licorice.

Lay out a piece of waxed paper or parchment paper, I find it easier to draw the antenna before I try to pipe them. put melted chocolate in a small Ziploc bag or even better is a squirt bottle (you can get them at kitchen and beauty supply stores.