Diamond Diva , Hopefully your cats will break their habit of chewing the ends of the leaves, because Talira is correct. 😕
Lilies are very popular plants due to their beautiful flowers, but unfortunately, they are highly toxic to cats. If your cat eats or licks a lily plant, they are likely to develop kidney damage which, left untreated, can lead to kidney failure and death.
All parts of a lily plant are dangerous, including the leaves, flowers and pollen (even in very small amounts). A common way for lily poisoning to develop is when a cat brushes past a lily, causing pollen to fall onto their fur (which they later lick off and ingest).
There are a number of different types of lilies and all of them can be poisonous including the Asciatic lily (Lilium asiatica), Stargazer or oriental lily (Lilium orientalis), Tiger lily (Lilium lancifolium or Lilium tigirnium) and Easter lily (Lilium longiflorum). Peace lilies (Spathiphyllum species) are slightly less dangerous, but are also toxic.