you know that they tend to have a mind of their own.

But what do you do

when you need them to behave in a certain way?

Like in a movie, for instance.

Well, you train them.

Melissa Millett: He likes it up on shoulders.

Kirk Jarrett: Yeah. Melissa: Here you go, bud.

Kirk: So he'll sit up there,

and then in turn then you do your eyelines to the lens,

and then all of a sudden now he...

now you got that one-on-one.

Animal trainer Melissa Millett

and animal coordinator Kirk Jarrett

are two of Hollywood's go-tos

when a movie calls for an animal's performance.

They've worked with dogs, birds, skunks, and even buffalo,

but they say cats are the most difficult

to train for the silver screen.

Melissa and Kirk worked together on the 2019 remake

of Stephen King's classic "Pet Sematary"...

There are places in this world

that bring things back.

Where one particular cat character

named Church plays a starring role.

Training cats is a step-by-step process,

and the main tools are something called a clicker

and, of course, treats.

First, Melissa would teach the cat

to touch their nose to an object,

luring them with the treats,

a process called targeting.

She would then progress to having them move

to a marker on the ground.

Cat hits the mark, click, get a treat.

Narrator: She would start with the marker really close to the cat.

and then slowly move it further and further away.

She also used a training technique called "freeshaping,"

which doesn't involve luring the cats.

Basically, Melissa puts a mark down

and just waits for the cat to figure out what to do.

Melissa: It's a hot-cold guessing game.

It allows them an opportunity to

problem-solve and be in control.

I put a mark down, if they get on it,

they get a treat, so they think that they're training me.

When it comes time for the cats

to actually give their performances,

that's where Kirk comes in.

As the animal coordinator, his job is to make sure

all the animals are comfortable on set.

Kirk: Cats are sensitive to their environment,

so acclimation is key.

Everything from the air temperature

to chatter from the cast and crew

had to be taken into account.

The cats stayed with the trainers

across from the set in Montreal,

so they didn't have to travel very far

and so they could get used to the environment.

There was leashed walks for the cats

in the woods after,

the cats had "catios" and patios, and

really, they had cat wheels, they had it all.

The cats also needed to get comfortable

being around dogs.

I bonded them to dogs,

and I brought them out one at a time with the dogs

so that they could look at the dogs and say,

"Oh, these guys are having fun, this is cool."

And having fun is one of the biggest

secrets to successful cat training.

Melissa: Knowing how to build their confidence

so they enjoyed the work,

and making it fun so they'll,

you know, play my silly games and enjoy.

For "Pet Sematary," Melissa and Kirk

had an unconventional casting process.

They rescued five cats to play the role of Church

but ended up predominately using just

two different cats throughout the movie.

The other three filled in for a few scenes

that didn't require close-ups.

Now, a bit of a spoiler here if you haven't seen the movie.

Tonic, a 10-month-old, was selected to play

the living version of the cat

because he was more active and outgoing...

Melissa: He still had a cute kitten-y face,

so he couldn't play the evil guy.

And 4-year-old Leo

was picked to play the undead version.

He's a calm cat, and he sits, he stays, he looks,

and that is what you see in the poster,

that's what you see on the trailers.

Both cats had never been in a movie before,

and a lot of work went into prepping them

for their acting debuts.

That included a healthy dose of makeup

to give Leo a bloody and gory look.

We had to ruffle him up,

we had to do some texture with blood,

and we had to make him look like

if he had been run over by a truck.

And since Tonic had to look exactly like Leo,

they added some brown-colored, pet-safe dye to his chest.

The makeup was American Humane Society-approved

and actually served as a treat for the cats as well.

Melissa: There was edibles and food that we put on the cats

so that when they licked themselves, it became a meal.

And because of all that hair and makeup,

they also needed a daily bath,

which required training all its own.

They first had to be OK with water.

They used a technique called counterconditioning,

which took about two months.

Melissa: We had catnip parties in the bathtub

to make the bathtub a nice place,

and then the next we would have

the most delicious treats that we would find,

and we would put two drops of water on them,

and then four, and then a little bit of a sprinkle.

In "Pet Sematary," Church also has to hiss a lot,

so how do you get a cat to do this on command?

They rewarded him whenever he did this behavior

on his own, naturally.

Sometimes a snake toy was used to elicit the response.

And Leo, based on his personality,

was a natural at being the undead Church,

hissing and swaying.

Leo has a personality that was...

positive towards the hiss.

He is kind of like a growly kitty.

He has that motion. He has that tail wag.

That's who he is. That's his character.

The production team used very little CGI

since the cats were so good at their job,

and each cat had their own strengths and weaknesses

based on their characters.

You know, it was difficult

to get Tonic to sit still,

and it was difficult to get Leo to move.

Throughout the entire filming process,

a representative from the Humane Society

was on set as part of the animal team

to make sure the cats were also safe and happy.

And after wrapping production,

Tonic seemed to have caught the acting bug.

When the movie was done,

he was leaping through the house

trying to coax me to play with him,

and he rode my big-screen TV right to the ground.

So I think Tonic wants to be a movie star again,

he likes the attention.