 Impala are symbiotically related to oxpeckers , which feed on ticks from those parts of the antelope 's body which the animal cannot access by itself ( such as the ears , neck , eyelids , forehead and underbelly ) . The impala is the smallest ungulate that oxpeckers are associated with . In a study it was observed that oxpeckers selectively attended to impala despite the presence of other animals such as Coke 's hartebeest , Grant 's gazelle , Thompson 's gazelle and topi . A possible explanation for this could be that because the impala inhabits woodlands ( which can have a high density of ticks ) , the impala could have greater mass of ticks per unit area of the body surface . Another study showed that the oxpeckers prefer the ears over other parts of the body , probably because these parts show maximum tick infestation . 
