| The outstanding feature of sebaceous glands is their holocrine mode of secretion, involving complete disintegration of the sebaceous cells. |
| In Chiroptera and Insectivora, the holocrine glands can form glandular complexes. |
| Various holocrine and tubular glands have been observed, but nearly all are small and inconspicuous. |
| The exception is the holocrine uropygial gland, or preen gland, which is located on the back just in front of the tail and secretes oil for grooming the feathers. |
| Sebaceous glands are termed holocrine because their secretion involves complete disintegration of their cells, which are constantly replaced. |
