Do Deer Eat Bugs and Insects?

Yes, deer will eat bugs and insects, but this does not make up a large proportion of their diet. Most species of deer are believed to be herbivorous. However, more evidence suggests that deer will eat small animals, including bugs and insects, just as the first species of deer used to around 30 million years ago.

Many people are shocked to hear that deer, often presumed to be strict herbivores, eat bugs and insects. However, deer are actually much less fussy with their diet than was previously believed. 

Though they are herbivores most of the time, deer do eat meat, and can eat any insects or bugs, too. Ground-nesting birds are at risk of deer eating their eggs or hatchlings, for example. 

Deer aren’t really equipped to kill, but there is ample footage of deer eating squirrels, rabbits, and other small animals. Knowing this, it probably comes as no shock that deer are not too particular when it comes to which bugs they eat. Insects and bugs are easy food for deer, as they do not require hunting but provide some contrast to their otherwise herbivorous diet.

What Bugs and Insects Do Deer Eat?

Unsurprisingly, the foliage that makes up the majority of the diet of a deer is most likely covered in tiny bugs, so even if the herd did not mean to, deer are undoubtedly eating bugs and insects all the time.

The bugs and insects that deer consume are significantly dictated by the kinds of trees they are eating. Deer tend to love munching on the leaves and branches of maple, hazel, oak, and birch trees, and a considerable variety of aphids, beetles, shield bugs, and flies live on these trees.

It also depends on the herd of deer and their environment, as the mammals tend to adapt to their environment pretty well and will make do with the food sources available to them.

Since deer don’t tend to go out of their way to eat insects, there is little to say about whether there are bugs that deer prefer to consume. For the moment, we can only assume that deer do not mind the presence of bugs on their foliage and can take some nutrients from them.

Deer can also eat caterpillars and spiders since these also tend to live on the trees from which deer take their leaves, shoots, and bark. If they eat from shrubs closer to the ground, deer will eat the worms and ground bugs that come with the greenery, too. It seems as though they really aren’t fussy!

Why Do Deer Eat Bugs and Insects? 

Deer are known as ‘ruminants’, which means that, much like cows, they ruminate or ‘chew the cud’. This means that as deer begin to feed in the pasture, they eat impressively fast. A deer can fill its stomach in under two hours, which, given its size, is no small feat!

Its four-chambered stomach means that deer can gather a lot of food and then digest it later.

As a result of this quick eating process, deer have pretty hardy stomachs. This means that they can ingest bugs and insects without much trouble, despite their stomachs being designed for a diet of primarily foliage. 

So, one reason why deer eat bugs and insects is simply that they eat quickly, and the vast amounts of green material they consume come with a side of bugs and insects.

However, if we also look at the evolutionary history of the deer, there is plenty of omnivorous behavior to consider. The earliest forms of deer are thought to have eaten plenty of insects and bugs (as well as eggs, birds, and small mammals) rather than solely plant matter. 

Though we think of deer as herbivores, some of this behavior is definitely still seen today.

It is thought that deer continue to eat bugs and insects from time to time to keep the option of carnivory available to them. Their flexible diet means that they can adapt to their surroundings more efficiently and are more likely to survive than if they were to be 100% herbivorous.

So, if there was a shortage in the greenery that makes up the majority of their diet, they could instead eat small animals, whether that be bugs or something larger.

Deer seem to be what we might refer to today as a flexitarian. Most of the time, deer are herbivores. However, deer are able to digest any bugs and insects, and if deer find accessible sources of energy such as bugs and insects in the wild, they will most likely eat it. 

Though for the most part, their diet is made up of plants and trees, consuming insects, bugs, and other small animals keeps deer open to changes in their environment.