My dad bought a plot of land next to the farm which was known locally for tick infestation. On occasion we’d bring the sheep off it to find them, the lambs especially, absolutely covered in ticks. We even saw ticks on ticks! We’d dip the sheep and lambs twice a year with anti-tick solution, you’d have to bring them down twice, once for the lambs and once for the ewes as the solution had a strong aroma that masked their own smell so you had leave one of the pair with their own smell to let lambs find their mothers or vice versa
Like most blood feeders they inject an anticoagulant into their victim but with that many ticks the lambs would have “watery” blood – whereas normally blood feels sticky as the platelets begin to bind, their blood was more like undiluted Ribena.