Drains can have nasty smells for various reasons. A pipe could be blocked or damaged and could be causing a build-up of waste water, sewage, or fat deposits.
Drains block for a variety of different reasons, the main common ones are damage to the drain, grease and fat build up, excessive use of wipes or foreign objects becoming lodged.
In a soakaway drain the water is not deposited into the main sewer system but is instead deposited into a pipe in the ground, the idea being that the water will soakaway. Typically soakaway drains are used for rain water only.
Jetting is the most effective way of clearing a drain for a number of reasons. The first being that jetting offers substantially more force in removing a blockage and second is that when using rods there is often a risk they can break and become trapped, creating more of an issue.
Typically if a drain rod is not too far into the drain, a bit of persistence with a jetter and with some skill means you can hook the better round the rod and bring it back. In most occasions we can do this, otherwise excavation work will be required to remove the rod.
Drains can offer a sanctuary for rodents, the constant food supply they can receive from houses flushing food waste down their drains offer a stable food supply. The other reason is warmth being only a few feet under the ground provides a warm sanctuary for rodents to breed and gain access to a property.