As has been mentioned the invasion of moles is taken from the Annales of Cambriae written around the 10th century and it predominately focuses on events in Wales, although it does mention some events from the rest of the UK and elsewhere.
Online copy of Annals
Info on the Annals
"Bread failed in Ireland. Vermin like moles with two teeth fell from the air and ate everything up; they were driven out by fasting and prayer."
The way the annals are written and the fact they mostly focus on events in Wales means you could also read the above quote as 2 separate events, like so:
In 896
Bread failed in Ireland.
while
(In Wales) Vermin like moles with two teeth fell from the air and ate everything up; they were driven out by fasting and prayer.