The Greek word that we have translated as ‘slithering animals’ herein, is herpeton…
It’s where we get the English words reptile and it’s the root of the word herpetology (a study of reptiles).
However, ancient peoples didn’t use this word to describe just cold-blooded animals.
Rather, it’s what they called any animals (including insects) that slithered or crawled on the ground.
Notice, for example, that when describing the types of creatures that the IsraElites were forbidden to eat (in the book of Leviticus)…
Listed among the herpeton are insects, weasels, and mice.
So, this is why we have commonly rendered the word herpeton as slithering animals.
You will see that we have taken a similar liberty with the Greek word peteina, which is usually translated birds but literally means winged creatures…
Because bats are listed among them in Leviticus.
So, whereas modern science may have grouped all animals into types such as mammals, reptiles, birds, amphibians, insects, fish, etc., The Bible groups them into flying creatures, wild animals, cattle, slithering animals, and things that live in (or come from) the water. This difference doesn’t appear to be the result of a lack of recognition on the part of Bible writers of basic animal types. But rather, it stems from the ways they were grouped by ancient peoples to describe all possible animal species.