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Smokey loves sunny spots for catnapping. Chester chooses chicken. Summer likes to wear dresses and hang out in airports.

OK, Summer's a little unusual, but her preferences are just an example of the many different things that make cats happy. From snuggling with their favorite humans to swirling around our legs at mealtime to chatting with us about their day, cats express happiness in a surprising variety of ways.

"Every cat is an individual, so it's going to vary from cat to cat," says behavior expert Dr. Debra Horwitz, a veterinarian, lecturer and author. "Some cats like when you spend time with them. If they're cuddle kitties, they like to sit on your lap. If they're playful cats, they like if you engage them in interactive games."

While there's no doubt that cats love their food, many of them will choose human companionship over a meal or treat, according to a study by the Human-Animal Interaction Lab at Oregon State University. For both pet and shelter cats taking part in the 2016 study, social interaction with humans was the preferred stimulus category for the majority of cats, with food taking second place.

Happy cats snuggle close, purr, bump heads with us (known as bunting) and give slow blinks, communicating affection and trust.

Sofiya and Mollie follow owner Sally Bahner around the house. Sofiya "meeps" when Bahner comes into the room. Mollie reaches out and "combs" Bahner's hair. Her cat Tekla hops onto the counter so they can have a conversation.

At their Florida home, Frank and Relina Sockman's cats R.J. and Abby enjoy happy hour with the couple. "We all go to the lanai to kick back," Frank says.

Janiss Garza's Abyssinian cat Summer, a star blogger, makes therapy visits and frequently travels with Garza to conferences. Summer loves strutting her stuff, whether it's in a hospital, airport or convention center.

Cats play favorites when it comes to letting us know who makes them happy.

Sandra Toney is the one who does everything for her cat Angel, but Toney's husband, Ray, is the apple of Angel's eye: "All her love goes to him," says Sandra. "She lays across his legs every time he sits in his recliner and has a look that says, 'He belongs to me.' "

As Angel demonstrates, being in touch with their people — literally — is an important part of feline happiness.

Brigitte Cowell Moyne's Savannah cat, Zari, sleeps in bed with her, sprawling on top of one arm to keep her in place. Teo, a Peterbald who loves Moyne's daughter, sleeps curled around Lola's head.

Purple sleeps next to Alison Taub, purring as she pets his head, the back of his neck and his throat. Purple is normally high-strung, Taub says, so when he relaxes and snuggles, purrs and "talks" to her, she knows he's happy.

Routine also makes cats happy.

Liz Moe's Miss Kitty enjoys watching her litter box being cleaned. That makes sense, Horwitz says. She believes cats are happy when their life is predictable. And that includes knowing when the litter box will be clean. It's not unusual for cats to wait for their box to be scooped and then immediately jump in to use it.

People, food and routine are important to cat happiness, no doubt, but here are a few more of their favorite things: boxes to sit in, batting at a small ball or wadded-up piece of paper, special toys.

Gail Parker's cats Leo and Athena enjoy loving on their dog buddy Daisy.

But Kim Hundley may have the real answer to what makes cats happy: "Doing whatever they want."