Bats

• Type: Magical Creature, Potion Ingredient
• Owners: N/A
• Maker: N/A

Bats in the wizarding world appear to be physically identical to their non-magical, or Muggle, counterparts. They are nocturnal, flying mammals that are commonly found in dark, secluded places such as caves, dungeons, and dense forests. At Hogwarts Castle, they are a common sight, contributing to the ancient and magical atmosphere of the school, particularly in the Great Hall and the Dungeons.

While not possessing overt magical abilities in the same way as a Phoenix or Hippogriff, bats and their body parts are utilized in several significant magical applications.

• Potions Ingredient: The spleen of a bat is a known Potion Ingredient. It is required for brewing the Swelling Solution, a potion that causes any object or creature it touches to swell dramatically in size. Hogwarts students, including Harry Potter's class, use bat spleens during their second year Potions lessons with Professor Severus Snape.
• Inspiration for Spells: Bats are the basis for the infamous Bat-Bogey Hex. This powerful Hex transfigures the target's bogeys into large, black bats that proceed to fly out of the victim's nose and attack them. The spell is a signature move of Ginny Weasley, who became well-known at Hogwarts for her proficiency with it.

Bats have a long-standing presence in the wizarding world, often associated with Dark Magic and dark places. Their nocturnal nature has linked them to creatures like Vampires, an association noted on a Chocolate Frog Card that Harry Potter observed on his first trip aboard the Hogwarts Express. They are a persistent feature of the Hogwarts environment, having been seen fluttering around the enchanted ceiling of the Great Hall and residing in the Dungeons for generations. Bats also serve as a mascot in the magical sport of Quidditch; the Ballycastle Bats are a professional team from Northern Ireland whose symbol is a large black bat.

Throughout the series, bats serve several distinct purposes:

• Atmosphere: They are frequently mentioned to establish the gothic and ancient ambiance of magical locations. Their presence in the Hogwarts Dungeons, the Forbidden Forest, and the dilapidated Shrieking Shack enhances the mysterious and sometimes foreboding atmosphere of these places.
• Characterization: The comparison of Severus Snape to an “overgrown bat” is a recurring literary device used to describe his appearance, movements, and ominous presence. His billowing black robes are often said to make him resemble a bat in flight, reinforcing his intimidating persona.
• Plot Device: The Bat-Bogey Hex is significant for demonstrating Ginny Weasley's formidable magical talent and assertive personality, which earns her respect from her peers and an invitation to the Slug Club from Horace Slughorn. The use of bat spleens in Potions class provides a moment of typical school-day activity at Hogwarts, grounding the magical world in a relatable educational setting.

In the film adaptation of Harry Potter and the Order of the Phoenix, Ginny Weasley is shown casting the Bat-Bogey Hex on Zacharias Smith in the Room of Requirement to stop him from questioning Harry Potter (film). She also uses the hex on Cormac McLaggen in the film version of Harry Potter and the Half-Blood Prince (film). The visual comparison of Severus Snape to a bat is heavily emphasized in the films through Alan Rickman's portrayal and the costume design of his perpetually billowing black robes (film).