Certain reptiles such as chameleons and caterpillars are what are gorillas scared/afraid of. They are also afraid of water and will cross streams only if they can do so without getting wet, such as by crossing over fallen logs, and dislike rain.

if you are to trek gorillas in Uganda in Bwindi Impenetrable National Park & Mgahinga Gorilla National Park, Rwanda in Volcanoes National Park or the Democratic Republic of Congo in Virunga National Park and Kahuzi Biega National Park.