Only months after the release of Billie Eilish's second album, Happier Than Ever, the pop star has already began work on her third LP, according to her brother and creative partner, FINNEAS.

In an interview with Rolling Stone to promote his new album, Optimist, FINNEAS said that he and his sister were "really excited to start working on" Eilish's next album. When questioned about their progress, the artist said they had "interesting skeletons" for songs written, but were "not sure what animals they are".

“We’ve got the net in the ocean, and we’re picking up detritus,” he told the publication. “And then you sift through all that, and you pick out the treasure, and then you have an album. I’m really excited. I think we’ve got a lot to say.”

Back in July, Eilish's second album, Happier Than Ever, was released to great success. In addition to its title track, the album was supported by singles 'My Future', 'Your Power', 'NDA', 'Therefore I Am', 'Lost Cause', and 'Male Fantasy'.

When discussing the album, Hot Press writer Ed Power states, "together with her producer and brother Finneas O’Connell, Eilish has crafted a thrillingly introverted, irresistibly stark and profoundly woozy collection".

FINNEAS noted that even if he and Eilish were able to complete the record in time for the forthcoming Happier Than Ever tour- which kicks off this February- it wouldn't be released until long after they wrap up, squashing any potential rumours that the third album could arrive in 2022.

“This tour is this album,” he told Rolling Stone. “We’ve played some festivals, but we haven’t done Billie headliner solo shows, and we’re really excited to play Happier Than Ever on the road. So even if it’s in the can by February, we’ll [delay it] for a little bit. Because I like letting projects breathe…

“You don’t want to step on the toes of an album like that. You make your stuff mean less, I think, when you do that.”

The duo will be taking the Grammy nominated Album of the Year on the road throughout 2022, playing shows across North America, Australia, New Zealand, and Europe, with two shows set for Dublin's 3Arena on June 4th and 5th.

The 19 year-old recently made history as the youngest recipient of PETA's Person of the Year for 2021 due to her work championing veganism in fashion and food. Eilish, who is also vegan herself, earlier this year persuaded noted fashion designer Oscar da la Renta to go fur-free after making her dress for the 2021 Met Gala, a moment she describes as a career highlight.

She also has launched her own 100% vegan Nike sneakers in September and released a perfume that contains no animal-derived ingredients and was not tested on them.

Tomorrow, December 11th, Eilish will make her debut as Saturday Night Live host, as well as perform some songs from her album.

On Optimist, Hot Press shares that "FINNEAS has a crisp, expressive voice and a knack for glossy angst. He is all about the heartfelt twang and wants people to know immediately what he is singing about, giving his songs an immediacy."