Ah, but how many one pound bags of concrete could it hold??

Why bags of anything? This is a poor way of communicating weight. Just say "a modern passenger car".

https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.10332

If you put your finger in front of a garden slug it may try to eat it, it's a very odd sand-paper sensation but I never knew why.

What an odd example. A mid-sized car would have been much clearer.

I know people like to talk about “how smart” the butterfly or whatever is for “adapting itself” to whatever environment, and it is cute, but there is a practical engineering choice between delicate design and brute force.