You can't see *Streptococcus thermophilus* bacteria with the naked eye! They are microscopic, meaning you need a microscope to see them.

Here's what they look like under a microscope:

* Shape: They are spherical, like tiny balls.

* Arrangement: They usually grow in pairs, called diplococci, or in short chains.

* Size: They are about 0.5-1.0 micrometers in diameter.

However, you can see the effects of *S. thermophilus* on yogurt:

* Texture: The bacteria produce lactic acid, which makes the milk proteins (casein) clump together, creating the thick, creamy texture of yogurt.

* Taste: *S. thermophilus* also contributes to the slightly tangy flavor of yogurt.

So, while you won't see the individual bacteria, you can enjoy the results of their work!