There are other bugs that can be mistaken for bed bugs. The bugs that are often mistaken for bed bugs are bat bugs and carpet beetles. Carpet beetles are smaller than bed bugs. The average carpet beetle is an eighth of an inch in length (an average bed bug is only a quarter of an inch). There are other physical differences between carpet beetles and bed bugs, including their coloring. Carpet beetles have white and yellow-brown scales and tufts of hair on the back of their abdomen. There is also a significant behavioral difference. Bed bugs feed on blood while carpet beetles feed on substances like carpet and woolen fabric.
Bat bugs and bed bugs look extremely similar but there is a trick to identifying a bat bug. If you look at the length of hairs covering the thorax you can see that the length of the bat bugs hairs are longer than the width of its eyes; while a bed bug has hairs that are smaller than the width of its eyes. It is easiest to see this difference if you are able to get the bugs under a microscope. A pest professional may be need to distinguish between these two pests.