You may have lovingly prepared your flower bed for your flowers, but many creatures just see freshly tilled and easily penetrated soil. There are many types of animals and insects that make their home underground and consequently dig holes in your soil.
Identifying the cause of the hole is the first step to taking care of any creatures that may be making holes in your soil. Observe the size and shape of the hole; this will give you a rough idea of the size of animal that made it. Worms leave casings next to a hole. Digging animals leave mounded soil around the hole. Check for paw or other prints in the dirt.
Some holes in your soil may be beneficial. Worms aerate soil as they dig through your garden and the casings they leave being are nutrient-rich, improving the soil. These holes are small, generally under a 3 mm (1/4 inch) in diameter.
Moles or voles, which are small rodents, make their homes under the earth, disturbing the roots of your plants and causing them to weaken or die. Dogs and squirrels may dig holes in your garden to store food for later consumption.
A wire mesh set at least 15 cm (6 inches) under the ground and extending at least 75 cm (30 inches) above the ground protects your garden against tunnelling animals. Use traps for voles and moles, set inside the holes. Place wire mesh under and over tender bulbs to protect them from foraging animals.