> Biological materials are hard to grow and store. In general, many diseases are highly species specific and/or affect only certain cell types. When you don't h

> Biological materials are hard to grow and store. In general, many diseases are highly species specific and/or affect only certain cell types. When you don't have a suitable cell line, the only real option is to keep live hosts. But these hosts could cross-contaminate other species/cell lines within the lab facility. Bat physiology is very different from most other mammals. If you want to study viruses in bats, it makes sense to use real animals, because you can be certain that the virus replicates in vivo, but it can be difficult to find a good in vitro environment.