Ticks & fleas
I believe the answer is:
parasites
(Other definitions for parasites that I've seen before include "They live off other organisms" , "unwelcome guests" , "Passengers" , "Hangers-on" , "they need indulgent hosts" .)
I believe the answer is:
parasites
(Other definitions for parasites that I've seen before include "They live off other organisms" , "unwelcome guests" , "Passengers" , "Hangers-on" , "they need indulgent hosts" .)