They both can absorb water from the air around them.
The fancy pants word for this characteristic is “hygroscopic”.
On rainy days you may find yourself having to coarsen your grind to get the pour that you usually get on a dry day.
This is also why we don’t recommend storing your coffee beans in the fridge. Because we live in a warm sub-tropical environment, it’s always going to be a challenge keeping your beans at their optimal freshness for any length of time. But keeping them in the fridge speeds up the ageing process. Every time you open the cold container, the coffee beans immediately attract the warm moist air in your kitchen like a magnet.
Find the darkest, lowest shelf in your pantry. If you can, invest in a vacuum storage container. (Yes, we use them. Yes, we sell them here too.) This will give those sweet little beans a little bit more shelf life for your enjoyment.
And leave the poor little Thorny Devil alone if you come across him in the Simpson Desert.. he’s busy getting himself a drink.