If you share your home with a cat, especially a longhaired one, you know the occasional hairball is part of life. They’re unpleasant to discover in the dark, but in most cases, an occasional hairball is a normal result of grooming.

Cats’ tongues are covered with tiny, backward-facing spines called papillae, made of keratin, the same material as human fingernails. If you’ve ever gotten a kitty kiss, you’ve probably felt those rough little hooks. They help cats groom themselves by pulling loose fur from their coats.

Grooming is soothing for cats and helps keep their coats clean while also regulating body temperature. However, the fur they ingest can sometimes condense in their digestive tracts and form a hairball.

Despite the name, hairballs usually aren’t round. They’re often narrow and tube-shaped, more like a small sausage, because they take the shape of the esophagus as they come back up. Since fur isn’t digestible, cats have to get rid of it one way or another.

Longhaired cats are more prone to hairballs than shorthaired cats, though any cat can get them. Kittens usually don’t have hairballs because they haven’t had enough time to accumulate large amounts of fur in their systems.

Experts say it’s normal for a cat to vomit up a hairball every few weeks. Before bringing one up, a cat may seem off for a day or two. The process can affect the digestive system and sometimes cause temporary diarrhea or a reduced appetite.

As unpleasant as they are, occasional hairballs are usually better out than in. The real concern is when swallowed fur moves deeper into the digestive tract and gets stuck.

Warning signs include reduced appetite, lethargy and repeated hacking without producing anything. Blockages from hairballs are rare, but they can be serious and are something to watch for, especially as cats get older.

Regular grooming is the most effective prevention, particularly for longhaired or senior cats that may struggle to keep up with their coats. Brushing can also become a bonding activity if introduced gradually, with a tool your cat tolerates well, and stopped when your cat has had enough.

If your cat’s grooming habits seem to decline, it’s also worth checking for dental pain or mouth discomfort, which can make self-grooming harder.

Hydration can help, too. Cats aren’t naturally driven to drink a lot of water, so adding more moisture to their diet can make a difference. Feeding canned or raw food and adding a little warm water can help increase fluid intake, while reducing dry kibble may also help. A moisture-rich diet can support not just digestion, but kidney health as well.

So if your cat occasionally leaves behind one of those tidy little fur deposits, it may not be pleasant, but it is often a sign that the digestive system is doing exactly what it was designed to do.