if it is happening during the night, a vole, mole or mouse.............daytime squirrels............................I would try making it hot..........over top of the dirt..............some hot sauce & 1 qt water and spray..........if you have some old pepper any kind, they don't like it..................sprinkle it over where you planted those seeds..............you also could put some screening over it until the start to open. Once they open they will not like 2 tablespoons dawn & 1 qt water on them to keep them away. Happy summer.