London, Aug 25 - Hollywood actress Denise Richards is upset her daughters are going to school because it means they are no longer babies.

The 'Wild Things' actress who has two girls, Sam, five, and four-year-old Lola, with ex-husband Charlie Sheen says spending the day apart from her kids is hard, reports femalefirst.co.uk.

'It's bittersweet. Sami starts kindergarten, which I cannot believe, in a couple of weeks. I'm so sad about it,' she said.

Richards, 38, is shocked at how quickly the girls have grown up, especially Sam.

'I can't believe how fast five years have gone. I'm very proud of her and very happy, but from here on she's in school,' she said.

In the absence of her daughters, the actress is showering her attention onto her dogs and often opens her home to stray pooches.

'I've always been that way. Ever since I was little I always brought home every little stray dog who didn't have a home. My daughters love animals as well, so I can't help it,' she said.