You need Shovels to dig for treasures and energy on your neighbors' lands.
There are 3 kinds of Shovels:
• Regular Shovels
• Golden Shovels
• Mega-shovels
Your shovels will be used up in the following way:
regular >> golden >> mega-shovels.

• Regular Shovels
You can use 300 free regular shovels each day (5 shovels at one neighbor's station).
Any bonus shovels that drop while digging are added to the daily 300 limit.

• Golden Shovels
They can be purchased at the Market (Buildings >> Expansions), crafted in the Golden lighthouse, or exchanged for Collections.
Golden Shovels will be used automatically if there are no regular shovels available. You can use 1000 Golden Shovels a day.

• Mega-shovels
They can be found at the Market (Buildings >> Expansions).
Mega-shovels will allow you to continue digging even when you’re out of other shovels.
They also can be used after you’ve reached your 1000 Golden Shovel limit.

Each neighbour's land can be dug on only 300 times each day (by all visitors).
If your neighbor has a shovel icon on his/her picture, this neighbor still has daily digs available.
But even if your neighbors’ daily 300 treasures have already been taken, you can still dig at their land using Mega-shovels.