 Many pelican parasites are found in other bird groups, but several lice are very host-specific.Healthy pelicans can usually cope with their lice, but sick birds may carry hundreds of individuals, which hastens their demise.The pouch louse "Piagetiella peralis", which occurs in the pouch, so cannot be removed by preening, is usually not a serious problem, even when present in such numbers that it covers the whole interior of the pouch, but sometimes inflammation and bleeding may harm the host.