Use Access Science, using phrases or words like "sow bugs" or "pill bugs" to get a brief article that describes these arthropods. The quotation marks make the encyclopedia search for the phrase rather than the individual words. The citation form at the foot of the page will show how to cite the piece in the electronic encyclopedia.
You may also use CREDO, a group of encyclopedias, to find materials about these crustaceans. Isopods seems to work better as a term than Isopoda, pill bugs or sow bugs in this set of resources.
Use Agricola or CAB Abstracts to find more scholarly articles related to the animal and what else you are interested in, such as the word (behavior OR behaviour).
It helps to use the term terrestrial in your search, since there are many members of Isopoda that live aquatically in either fresh or salt water. In common usage, some of these crustaceans that roll into balls when challenged are called pill bugs, or roly-polys, rather than sow bugs, but this is not a scientific distinction.
For popular articles, use ProQuest or Academic Search Complete, with a similar search pattern, such as (sow bugs or pill bugs or woodlice or wood louse) and (behavior or behaviour).
You'll see that the popular articles, in something like Organic Gardening or Discover, are not as densely written, not as much supported by other sources, and are more likely to include illustrations. by contrast, the more scholarly articles will have support from other sources, are written in terms that a professional audience will understand, and are more likely to include charts, tables or graphs.
In the databases, if the text of the article isn't attached to the citation, use the "Find It" button to help locate the items. Many of the journals are available online.
Cite your sources as you work, It is far easier to keep track if you record the information about your sources as you go. We offer Refworks, Endnote Basic, and help in using them in the library. You can also use free citation managers like Zotero or Mendeley.