Ticks are a kind of large mite that sucks the blood of larger animals. Ticks leave their host between blood meals and it is not very likely that they will find the same host the next time they need to suck blood. The castor bean tick and the brown dog tick must have a total of three blood meals (as larvae, as nymphs and as adults). The pigeon tick needs a total of five blood meals. The risk of not being able to find the next host is quite large. Ticks get by laying many eggs and by being able to live a long time without food.

Three kinds of ticks can be especially troublesome: The castor bean tick, which is an outdoor species and brown dog tick and the pigeon tick which are two indoor species with dogs and pigeons as the main hosts, respectively. The castor bean tick and the brown dog tick are similar. The pigeon tick lacks the small dorsal shield which the other two species of this book have. It is bigger and has a different body shape.