Rats will live in your back yard for many reasons. Is there tall foliage? Bushes and flower beds? Are there vegetable gardens? A water feature or a pool? Do you eat outside a lot? Do you have a bbq that has not been properly cleaned? Do you have a bird feeder? Do you have a pet that eats outside? Do you have children? These is just some of the reasons rats can be on your property. There are many more and the rats will come for all of them. You can remove your bird feeder and water feature, you can cut down your fruit trees and you can even stop eating outside and rip out all your gardens the rats will still come. They are attracted to human homes because they are biologically predisposed to do so. They actively search out human properties to infest in the hopes of finding human food, especially in an urban environment.
If you are dealing with a cockroach infestation or have suspicions thereof, contact Biehn Rat Control for a fast and effective complete eradication.
If you have rats in your back yard there are things you can do. Do not bother covering the burrow openings, they will simply dig new holes and they try to cover their burrows themselves with heavy objects for protection. They are natural burrowers and you cannot fight them underground. You can place poison and snap traps at the opening of the holes and this will likely catch a good number of rats. Putting poison directly into the holes can be very effective but if the poison is domestic the amount of poison is limited and not effective for a large-scale infestation.
Some repellents can be placed in the holes, clove and castor oil and citronella can be effective and if you do it studiously you may chase them away with the bad smell, this would be a great deal of work and the rats will burrow away from the smells and even try to seal off the burrow but if you are consistent with your application of whatever repellent you choose you may be successful with chasing off a small infestation.
If your exterior rat situation has reached the breaking point and you desperately need them gone then you need to call a professional extermination company that has specialists for rodent issues. The exterminator can inspect the area for activity in ways that the average person would not likely know about even with a very deep google investigation. The exterminator will find suitable places to lay down tamper-proof bait stations containing commercial-grade rodenticide. This chemical is a poison that causes internal bleeding and rapid dehydration of the rodent. This effect takes two to seven days to kill the rodent from repeat or one-time feeding poisons. After four weeks, possibly a few more, your rodent infestation will be over.