AceShowbiz - Calista Flockhart and Harrison Ford pull pranks on one another. The 59-year-old actress is called the "Scare Monster" at home because she can't resist playing practical jokes on her spouse - who she married in 2010 after eight years together - but the "Indiana Jones and the Dial of Destiny" star isn't afraid to get his own back on her.

"I'm called the 'Scare Monster' in my house because I hide behind every corner," Calista told the New York Times newspaper.

"And so Harrison will walk in, and then I'll go, 'Raaah!' And he'll go, 'W-uy-aah!' And then I die laughing. I'll put a plastic spider inside his big ice cubes in the tray, and then he'll drink it. But then I'll go to bed two weeks later, and he's out of town in Jackson, and I'll take the covers down and there's this little rubber scorpion. It's fun."

The "Feud" star thinks the key to their long-lasting romance is that she was "really content being home" as a full-time mom to son Liam, now 22, and she and Harrison can be "very independent" - much to the occasional dismay of the 81-year-old actor.

She said, "I didn't have the same dreams at the time, so we weren't competing with each other. We're very independent of each other in some ways. and probably incredibly codependent on each other in others."

"It scares him, I think, sometimes. When I first met him, he said, 'You are the most self-sufficient woman in the world, and I don't know how I feel about that.' I remember I said, 'What are you talking about?' Because I didn't recognise I was self-sufficient. The other reason it works is, we're both pretty introverted. We stay home a lot, homebodies, which is nice."

The former "Ally McBeal" star had adopted her son, a year before she met Harrison - who has four other kids from two previous marriages - and she thinks he has "evolved" into being a good father over the time they have been together.

She said, "I think he was a really good father in a lot of ways, and maybe because he was on Round 2 or Round 3, so he had matured and grown up and, I think, evolved into being a good father. He's such a good father to his kids now. I love his kids, my stepkids."

Despite their happiness, Calista insisted marriage isn't easy. She said, "We've had to work. We've had our ups, we've had downs like everybody else - mostly ups, which is good - and we just stay together. He's the person that I want to call when something happens. That knee-jerk thing where I have to call Harrison."