Nothing absent from what I can see as of yet. However, you may want to note the following...
https://en.wikipedia.org/wiki/Ratatoskr
https://en.wikipedia.org/wiki/N%C3%AD%C3%B0h%C3%B6ggr
The squirrel and the serpent are not to be confused. While Ratatoskr's name does translate roughly to something like "Drill Tooth" or "Bore Tooth", it does not gnaw on the Yggdrasil's roots as Níðhöggr does, and they are considered to be two entirely different entities.
https://en.wikipedia.org/wiki/Ratatoskr
https://en.wikipedia.org/wiki/N%C3%AD%C3%B0h%C3%B6ggr
The squirrel and the serpent are not to be confused. While Ratatoskr's name does translate roughly to something like "Drill Tooth" or "Bore Tooth", it does not gnaw on the Yggdrasil's roots as Níðhöggr does, and they are considered to be two entirely different entities.