The quills on mine are NOT rubber, but are a sturdy, hollow plastic. That being said, I'm sure a set of strong gums / teeth could make permanent indents in them because they are hollow. Each quill has a very tiny hole in each end (1.5 mm wide), probably for manufacturing purposes, but it's big enough that saliva or bathwater could get trapped inside and grow gunk if you aren't careful. Each quill is 3 5/8" long. The circular part that pokes into the hedgehog body is about 5/8" in diameter and slides 1" into the body. The ergonomic end for little fingers to hold is a 7/8" x 5/8" oval.
They're cheap thin plastic now, just bought this again and several other items. We have one these hedgehog toys from a couple years ago that has strong sturdy rubber quills. I am so disappointed in Learning Resources, that they are doing this to their products now. We used to LOVE Learning Resources products because of how strong and sturdy they were and have Tons of their old products. Unfortunately, we will not be buying from them anymore because they cared more to save a few pennies than to please their customers. Shame on you! We will stick with Lakeshore Learninng now for quality durable products.
The quills are a soft plastic. My 12 month old grandson wanted to chew on them, so we only let him play with the toy for a few minutes before putting it out of reach. He was a little too young for the toy at the time, but I think it will be fine next time he visits.