The black dirt in the kitten’s nostrils is very hard and is formed by the mixture of nasal secretions and dust. It is similar to human boogers and is a normal phenomenon. If excessive secretions affect the cat’s breathing, you can clean it appropriately. If there is not much secretion, there is no need to clean it specially. Generally, the cat will expel the dirt by itself.
Tips:
Pay attention to cleaning and reduce dust in daily life, so as not to affect the cat's health.