evidence: So, are geckos dangerous? Generally speaking, geckos are harmless to humans. They are gentle in nature and unlikely to attack. However, it is not unheard of for these lizards to bite if they feel threatened or in danger; merely acting out of self-defense and life preservation. Gecko bites are usually painless and not deep, but they can potentially transfer harmful bacteria, including Salmonella, which can cause an infection if left untreated. [...] While a gecko may attempt to bite you, it’s good to learn that they are mostly non-venomous. [...] If you were wondering whether geckos were dangerous, hopefully by now you will have learned that they are generally harmless to humans and rarely bite.