Extraverted & Introverted cat personalities vary. Some are sweet cuddlers~ looking for & loving attention while others are loners allowing you minimal interaction. Any or all of them may bite on occasion ~ as a way of communicating often catching us off guard.
Was that a playful nibble, a love bite or a warning of some kind?

Here are 4 Reasons Why Your Cat Is Biting

#1: Showing Affection

Hopefully this is why & what we prefer to believe is our cat[s] way of ‘loving’ us.

The best way to determine this is to note the situation and your pet’s body language.
Is he/she relaxed? Are her/his ears upright? These are non-aggressive tell-tale features.
If this is a ‘no-no’ in your world ~ don’t react by yelling or hitting. Just a simple & firm voice tonality “No!” and then remove/leave them ~ as a form of banishment from you. If you’re consistent, this can be enough to change their behavior over time.

#2 Play Biting

A quick bite from your cat may also be an attempt to play with you.
They learn this in their formative early days/time in their litter when they wrestle and nibble their brothers and sister kitten. As they grow within the litter they learn not to get too rough thanks to the squeals of their playmates ~ but kittens who are removed from their families too early [prior to 7-8 weeks of age] may not have learned these important ‘boundary’ lessons.
If you’d want to stop your cat from using their teeth here are 3 suggestions.
A] Ignoring a bite and walking away from them [a form of temporary abandonment from you] may be enough to “punish,” along with a stern “No!” & giving off ‘unwanted vibes’ from you.
B] Be consistent. Allowing biting sometimes and getting angry at other times sends confusing signals to your cat. Cat behavior won’t change without consistency.

#3 Overstimulation

Example: You’re relaxing on your sofa and your cat joins you and spreads themselves across your lap ~ prime petting position. You stroke your cat’s coat unconsciously for a few minutes while being distracted from a TV program…..then ‘BAM’…out of nowhere your cat delivers a hurtful bite & runs off [or doesn’t!].
Sometimes cats will use their teeth to do the talking. Had you been paying attention, you may have noticed the tail starting to twitch or the ears laying back slightly—both signs of ‘petting-induced aggression’.
It could be that your cat simply reached the maximum amount of affection and had enough, or perhaps your mindless petting was taking place in the exact same spot for too long. FYI: repetitive motion can often irritate and can even be painful to a cat, and/or can cause unwanted static electricity.
Avoid bites from overstimulation by being mindful of your cat’s petting preferences. It only takes a few times of attentive affection to figure out what kind of petting your cat prefers and what seems to bother them, and how long your petting at any given time is too long for them.

#4 Stress Induced

Many kittens are removed from their mothers too soon, and this can affect a variety of behaviors in their adulthood. Some cats who were weaned too soon as kittens self-soothe when they get stressed by suckling and nibbling. If your cat is suckling (usually on a piece of clothing, blanket or pillow), this is likely the reason.
Adult cats exhibit stress for a number of reasons and might react with biting.
If you’re bothered by it ~ introduce other distractions like cat toys or a treat.
You might find ‘Calming herbs’ like catnip, chamomile and valerian can also help reduce anxiety.