For air brick covers, add mouse vent to client work order invoice on top of what you ordinary pay for the job. This covers the direct cost.
 
Mousemesh prevents mice from entering a property via existing in-built air brick vents. This unique pest control innovation is one of the few truly preventative measures currently available.
 
• Easy to fit
• Hard and highly durable plastic frame
• Stainless steel insert ensures its durability in all weathers
• Can be fixed using screws or strong adhesive