Appearing Frequently
Infesting
noun, verbal noun
Animals exit the mountains into your land and never seem to die! They end up appearing frequently in your garden, eating all your yummy carrots and watermelons, and then make their exit back into the hills. They're infesting your home now and you don't know what to do!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
日本各地でクマが大量出没している。
Bears appear frequently in large quantities all over Japan.