The book of dragons page for Stormfly says "Has a blind spot right in front of its nose. Do not move and it will not see you." The arrow pointing to the tail says "Danger". This is transliterated from English, though not correctly, into Anglo-Saxon runes.
The book of dragons goes on to say Deadly Nadders have a magnesium flame, are aggressive and bad tempered. None of what Heather and Astrid are listing is on either of the pages.