Seal and Heidi Klum have become "inspired" to adopt by Sandra Bullock.

Seal and Heidi raise four children together - Leni, seven, Henry, six, Johan, five and two-year-old Lou. The married couple have their work cut out raising their young brood, but would never rule out adoption in the future.

Sandra has an adopted 18-month old son called Louis, and Seal says the actress has encouraged both him and Heidi to see the process differently.

"I was really inspired by Sandra Bullock, who we've become friends with. She came round with her adopted son and she's raising a little boy from Africa by herself. She's giving him a chance, but he doesn't know it yet, which is just awesome," he gushed in an interview with Closer magazine.

"We've talked about adopting, I've no idea where we'd adopt from but I think we will one day just not yet."

Seal has discussed the secret to his happy marriage.

He has been with Heidi for eight years, and with four children to raise, Seal says they work hard to keep the spark alive.

"We do have a lot of fun together, but you've got to. We lead such hectic lives, so we make the time we have together count," he said.

"We're best mates, the chemistry is great and we love spending time together family always comes first no matter what."