Henna, a temporary dye, or even animal fat, could be applied to make the hair more manageable.[24] Aside from henna, more common permanent dyes were based on natural substances and perhaps more unorthodox mixtures. To prevent graying some Romans wore a paste at night made from herbs and earthworms and pigeon dung was used to lighten hair. For example, to dye hair black, Pliny the Elder suggests applying leeches that have rotted in red wine for 40 days.[25]