Duration of tick activity.
D000818:Animals; D004739:England; D005260:Female; D012621:Seasons; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology*; D013045:Species Specificity; D013984:Tick Infestations / Q000662:veterinary*; D013987:Ticks / Q000502:physiology*