Ace Ventura: When Nature Calls

In the Himalayas, a failed rescue mission results in a raccoon falling to its death (a parody of Cliffhanger). Ace Ventura then undergoes an emotional breakdown and joins a Tibetan monastery. Once he has recovered, he is approached by Fulton Greenwall, a British correspondent working for a provincial consulate in the fictional African country of Nibia. Because Ace's presence is troublesome to the monastery, the Grand Abbot gives Ace excuses to justify his departure, and sends him with Greenwall.
Thereafter, Greenwall asks Ventura to find the white bat 'Shikaka', a sacred animal of the Wachati tribe, which disappeared shortly after being offered as dowry of the Wachati Princess, who is set to wed the Wachootoo Prince to form armistice between the two people. Accompanied by his capuchin monkey, Spike, Ace travels to Africa to search for the missing bat.
After arriving in Nibia and meeting with consul Vincent Cadby, Ace begins investigating his case, but must overcome his intense fear of bats in order to succeed. He travels to the Wachati tribal village, where he learns that if the bat is not returned in time, the Wachootoo will declare war on the Wachati tribe. Thereafter much of Ace's activity involves eliminating obvious suspectsâanimal traders, poachers, and a Safari park owner among othersâand enduring the growing escalations of threat between the Wachati and the Wachootoo. This proves difficult, and is made more so by other incidents including attempts to kill him, a series of exhausting tasks set by the Wachootoo, and the Wachati princess' attempts to seduce him.
Confused by the case, Ace consults the Grand Abbot via astral projection. Advised by the Abbot, Ace deduces that Vincent Cadby has taken the bat and hired Ace to divert suspicion from himself, having planned to let the tribes destroy each other so that he can then take possession of the numerous bat caves containing guano to sell as fertilizer worth billions. When Ace confronts Cadby with this knowledge, Ace learns he was hired as Cadby's alibi, and he is arrested by tribal security chief, Hitu. Shortly after, Ace calls an elephant to escape, and summons herds of jungle animals to destroy Cadby's house. Cadby then tries to shoot Ace, but is defeated by Greenwall who punches him in the face. Cadby escapes with the bat in a car, but Ace follows him in a monster truck. In pursuit, Ace destroys Cadby's car, leaving the bat cage lodged in a tree.
Ace, despite his chronic chiroptophobia, bravely yet dramatically returns the bat just as the tribes are charging on a field to fight until they notice the bat and kneel before it; and Cadby, watching nearby, is discovered by the Wachati prince, Ouda, and pursued by both tribes, later to be raped by an amorous silverback gorilla (the rape is mostly left to the viewers' imagination; they see the palm trees shaking in sympathy, but nothing else) The Princess is married to the Prince, who Ace had to fight as one of the Wachootoo tribal challenges. Moments later, it is discovered that the young bride is no longer a virgin, apparently on Ace's account. Both tribes then viciously chase after Ace, concluding the movie.

Question: What must Ace overcome his fear of?
Answer: Bats