In Ae. aegypti control efforts, it may be difficult to observe the nature of the
behaviour, and therefore for monitoring purposes it is often necessary to select
physical by-products of the behaviour rather than an observation of the behaviour.
Nonetheless, behaviours must still be operationally defined even if their direct
performance cannot be observed. It is only through the operationalization of each
behaviour that indicators can be developed to measure whether or not the behaviour
has taken place and to what extent it has been carried out.