Yes. They look almost similar in the pictures. Even the taste and smell are confusing to me. Fret no more, my dear blogger friend aka Master of Spices has answered the mystery for me!
Read her post to find out!
Here are the pictures of the two different types of seeds:
Fennel Seeds comes from the Fennel plant thus its anise flavour!
The Fennel Seeds
As you can see in the two pictures, Cumin seeds are smaller and darker in colour. (I thought they look thinner too!) They have a strong bitter flavour due to the abundant essential oil content.
The Cumin Seeds