There are a wide range of insects that can be found within the Nature Reserve – spring being a time when they are most plentiful; although, the late summer migration of dragonflies across the Strait is something to behold.
There are 33 species of butterflies including some of the most large and colourful like the Cleopatra, Red Admiral, and Two-tailed Pasha. Moths are also plentiful and early spring will see many caterpillars of the Pine Processionary Moth which create silken nests on pine trees. One to watch out for is the Hummingbird Hawkmoth as well as the Striped Hawkmoth. Spiders can be found in many of the tree trunks and crevices around the Reserve like the Gibraltar Funnel web Spider or Orb-weaving Spider.
When one thinks of the sound of summer in Gibraltar they immediately recall the persistent and comforting churr of the Cicadas. This time also sees the Mediterranean Coastal Snail on the tops of stalks and poles as they shut off to survive the hot dry summer period and the adult praying mantis out in the open areas of the Upper Rock hunting for food which includes large insects and lizards.