Have you noticed that your cat taps its tail aggressively when it's feeling a little grumpy? Why do cats wag their tail even when lying down – and when should you be afraid?

Every cat owner has been there.

You're chilling with your kitty, having a nice cuddle, when WHAM, out come the claws!

One of the key signs that this is about to happen is, of course, a slapping tail. But What is behind this behavior, though, and what makes your cat so unpredictable?

Cats Cat has hilarious reaction to his own reflection!

As always, TAG24's cat guide has the answers to yet another feline mystery!

We take a look at why cats wag their tails while lying down or even when they're sleeping, and when a tapping tail can be seen as a warning.

How can you avoid a scratch? Let's take a look!

Cat body language is a complicated and difficult to decipher thing, no matter whether you are talking about a kitty's ears, tail or whiskers. The simple wagging of a cat's tail is not the issue (after all, their tails are constantly moving), but when it's tapping against the ground suddenly and forcefully, you should be paying attention.

Cats will tap their tails upon the ground to indicate moodiness, irritation, or anger. These slaps are firm and sturdy, and will include slow and ominous waves from side to side. If you are patting your cat when it is lying down, and its tail starts to flick, you should back off.

Here's what a slapping cat tail could mean when it's lying down:

• Indecision
• Unease and fear
• Energy
• Anger
• Annoyance and irritation
• Aggression
• Pain

If your cat is crouching close to the ground while you are petting it, slowly flicking and tapping its tail, it may be scared, concerned, anxious, or angry. In the case that these slaps are slow, there is less of a reason to be concerned, but if your kitty is whipping its tail around quickly, it may be getting overstimulated.

Cats that are overwhelmed, annoyed, or angry, will display this waving, wagging, and flicking behavior. There is a strong possibility that this behavior could precede aggression, so it's best to be careful.

If your cat is starting to get annoyed with you, or it wants you to stop doing something, its tail can serve as a warning to be observed. Fast flicking is a bad sign, and you should back off. Slow tapping is a warning, but you can proceed with caution. Graceful, flowing movements, and a habit of touching you with its tail, indicates a happy and loving cat that can continue to be smooched.

In many cases, cats wag, twitch, or slap their tails because they are dreaming. We also have physical responses to dreams, particularly during REM sleep. The flicking of the tail is often also coupled with twitching, other physical movement, and squeaking.

When a cat is sleeping, it's not generally the best idea to wake it up or give it a cuddle. This especially goes when your interference has caused tail flicking. In the end, wouldn't you also get kind of annoyed if someone woke you up to touch your hair? In the case of a kitty, such annoyance could easily turn into violence!

If your cat starts thumping its tail when you are petting it, you should back off immediately and leave your furry friend alone. It really is that simple, and doesn't need to be overthought. Tail flicking can, as we previously discussed, be a warning, and such warnings should be abided by.

Don't get on your cat's nerves is the headline here. Back off and give your mercurial pet some space.

If it gets a bit wild and wants to play, whip out a toy, but don't be too intense and instead allow your kitty time to calm down.

If you want to avoid getting slapped around by your cat, always keep an eye on its tail. It's not unusual for a kitty to lash out suddenly, with very little warning, but if it is flicking its tail in an irritated or wild way, perhaps you should step off a little bit.

As with anything, when you own a cat, it's incredibly important to understand their body language and habits. Once you can differentiate between a happy flick and an angry tap, the sooner you'll reduce the risk of a sudden and unexpected scratching.