Cats can’t taste sweets.
Yep, also including most meat eaters and all felines from big to small. Because their diet has been mostly meat, the need to taste sweets just wasn’t necessary and the gene required to make part of the sweet receptor protein became ‘broken’. Those spikes, called filiform papillae, are what make cat tongues so rough and help them groom. We have them as well, they are just a lot smaller.
Source: Discover / Ed Yong