Here's why:

* Prokaryotes: Bacteria are classified as prokaryotes. This means they lack a membrane-bound nucleus and other membrane-bound organelles found in eukaryotic cells.

* Nucleoid Region: Instead of a nucleus, bacteria have a nucleoid region. This is a concentrated area of DNA within the cytoplasm, but it's not enclosed by a membrane.

* Eukaryotes: Organisms with a true nucleus and other membrane-bound organelles (like animals, plants, fungi, and protists) are called eukaryotes.

So, while bacteria have DNA, it's not organized within a nucleus like in eukaryotic cells.