Skunks are excellent burrowers. They have very long thick and strong claws that can burrow through gravel and clay. They are a serious wildlife issue because of their spectacular weapon granted to them by the sometimes confusing process of evolution. Why they developed this ability, aside from having a defence against predators, is entirely unknown. If there are skunks on your property, give Skunk Control a call.
Skunks are what is called a new world animal which means they are native to North America and not to Europe. They belong to the family Mephitidae and are among a number of animals with a spraying ability. However, there is no animal with such a highly evolved and developed system with such incredible accuracy, distance and potency. The smell can remain powerful enough to cause revulsion at only eleven parts per million. This is almost unheard of and is more powerful a smell than amber griss perfume. This mean you can wash the area of the spray and yourself a hundred times and still smell it potently. No one wants that smell on their property.
Dealing with a skunk under an inaccessible porch made of concrete is definitely a serious problem. While skunks can dig through gravel a wildlife technician cannot. If your deck is abutting anything close or is too high off the ground then the removal may be impossible. Even closing a deck off is not effective as they can burrow beneath any structure. The only way to prevent their activity structurally is with a process called trenching. Again, this process requires that the deck be out in the open with no inaccessible areas against a tree, fence or shed or wall of your home. If you can get into the space with a shovel and dig then you can get them out.
The process is simple enough. You dig a one foot by six inch trench around the whole of the decks perimeter excluding where it is attached to another structure. You will then attach galvanized water proof steel mesh of a gauge and thickness that will keep the animal out, to the edge of the top of the deck. Use bolts with wide washes to assure a tight seal. Lay the mesh down into the ground so that it is straight and tight. Bury the steel mesh one foot down and six inches out so as to prevent any burrowing animal from entering. If an animal is already under the deck you will need to cut out a square of mesh and attach a one way door. This is a device that allows the animal to vacate but prevents the animal from getting back in. If this process seems possible on your property it can permanently protect your structures from any wildlife and even rodents and insects.
If the only issue on your property is skunks then there is an alternative you can try. Skunks tend to come to properties with already damaged yellowing lawns to find an insect they prize called a Grub. The grub burrows into the roots of plants like grass and drinks the plants fluids directly. This makes them very fat and juicy and skunks love them. Doing a treatment in the spring for grubs will both make your lawn greener and get rid of skunk invaders as they will have no food to feed their young. Its a simple three step process. Aerate the lawn with a machine you can rent or buy, use a zero nitrogen fertilizer and if you still see yellow grass do a domestic insecticide treatment, it need not be strong, on your lawn. That will get rid of them in the long term and will keep skunks off your property.