Rearz adult baby bottle

[daddyb]

Where am I supposed to poke a hole?

What nipples can I buy at Wal-Mart/Target to replace the one they sent me?

I believe you are referring to the vent hole on the nipple. If you look at the inside of the nipple you will see a small flag of material. This this the vent hole. Find the other side of this tiny nipple and pole a toothpick through it and this separates the material enough to allow the vent to work properly.