Grubs are not the easiest creatures to find in Grounded, and unfortunately, they are most abundant in an area that is quite dangerous, near the large Oak Tree where the lab is hidden, near to where the explosion happens when you try to use the Mysterious Machine.
To get Grubs and Grub hide, make you way over to the Oak Tree and then look on the ground for fallen acorns. When you find one, smash it up with you hammer, then pick up the broken pieces of shell. You can now make a shovel, which you will need to get grubs.
How to find Grubs and Grub Hide
Now you will need to search around on the ground for small disturbances in the mud that look like something crawling along underneath. These are common enough in the wetter mud underneath the tree.
When you see one, dig it up with you shovel, then switch to your Ax or spear and bash the grub 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 that you can use to store water in, making your life easier as you try to survive each day.
The main things to be careful of in this area are all the spiders. These are the most difficult to deal with enemies in the game, so it is good to set up a Lean-To somewhere close, as the chances of you needing to respawn are pretty high. Make sure you set your new Lean-TO as your respawn point by interacting with it and clicking the “Set as Respawn” option.