There are over 2500 species of lice they reproduce very fast because Females lay up to 100 eggs which are cemented to the hair or feathers of the host with a clear fast drying glue which is secreted onto the hair or feather by the female immediately before she lays the egg. The eggs take about 3 or 4 days to hatch and the nymphs go through 3 larval instars in about 20 days before they reach maturity.
When you understand how quickly they multiply and that some do bit our pigeons your removing them can and will let your pigeons rest and on race day perform.
Removing lice form your loft is not very difficult. Today there are many products on the market that do a great job.
One product I used for many years was Perch Paint I was always amazed of how fast the product worked.
Today there are many good products on the market that will do the job just as fast.
Get rid of the lice and add a few yards to your speed.