Grubs are not the easiest creatures to find Grounded, and unfortunately they are most abundant in a fairly dangerous area, near the large oak tree where the lab is located, near where the explosion occurs when you try to use the mysterious machine.
To get the skin of the worms and grubs, head to the oak tree, then search the ground for fallen acorns. When you find one, smash it with your hammer, then pick up the broken shell pieces. You can now craft a shovel, which you will need to obtain grubs.
How to find grub worms and skins
Now you will need to search the field for small disturbances in the mud that look like something crawling underneath. These are quite common in the wetter mud under the tree.
When you see one, dig it up with your shovel, then switch to your ax or spear and hit the worm with it until it dies. You can loot the corpse for Grub Hide. Grub Hide is very important because getting some will allow you to build a canteen which you can use to store water which will really make your life easier when trying to survive every day.
The main things to watch out for in this area are all spiders. These are the most difficult enemies to deal with in the game, so it's a good idea to set up a Lean-To somewhere, as the chances of you needing to respawn are pretty high. Make sure to set your new Lean-TO as a respawn point by interacting with it and clicking the "Set as respawn" option.
