![If Holly (Ilex aquifolium) finds its leaves are being nibbled by deer, it switches genes on to make them spiky when they regrow. So on taller Holly trees, the upper leaves (which If Holly (Ilex aquifolium) finds its leaves are being nibbled by deer, it switches genes on to make them spiky when they regrow. So on taller Holly trees, the upper leaves (which](https://preview.redd.it/2lhyol78xu881.png?auto=webp&s=6cb1250c29f3406fc7644046bd81dc6f63b041d0)
If Holly (Ilex aquifolium) finds its leaves are being nibbled by deer, it switches genes on to make them spiky when they regrow. So on taller Holly trees, the upper leaves (which
![128,500+ Holly Tree Stock Photos, Pictures & Royalty-Free Images - iStock | American holly tree, Holly tree with snow, Holly tree winter 128,500+ Holly Tree Stock Photos, Pictures & Royalty-Free Images - iStock | American holly tree, Holly tree with snow, Holly tree winter](https://media.istockphoto.com/id/1403832782/photo/bluebird-eating-holly-berry.jpg?s=612x612&w=0&k=20&c=p5U28ba9b247LIE4So3_sntZC1WRE8x97G1dNa0IxZE=)
128,500+ Holly Tree Stock Photos, Pictures & Royalty-Free Images - iStock | American holly tree, Holly tree with snow, Holly tree winter
![Small Common Holly tree (Ilex aquifolium, European Holly) in Winter in a park in the UK Stock Photo - Alamy Small Common Holly tree (Ilex aquifolium, European Holly) in Winter in a park in the UK Stock Photo - Alamy](https://c8.alamy.com/comp/MC1ND0/small-common-holly-tree-ilex-aquifolium-european-holly-in-winter-in-a-park-in-the-uk-MC1ND0.jpg)