It is sometimes referred to as Australia 's smallest mammal .
The Northern or Koopmans Pipistrelle , Pipistrellus westralis , is possibly smaller , weighing on average around 3 g ( 0.11 oz ) .
It is sometimes referred to as Australia 's smallest mammal , although the Northern or Koopmans Pipistrelle , Pipistrellus westralis , is possibly smaller , weighing on average around 3 g ( 0.11 oz ) .