No, the ants are not feeding upon the aphids such as meat but are harvesting the sugary waste, like humans milking cows. The excrement of aphids and mealybugs is called Honeydew. Ants are the most notable insect to consume honeydew but others such as wasps will also eat it for a sugar source. 

Ants have a complex role with aphids and honeydew: 1-they do herd and protect the aphids from predators, thus reducing bio-control efforts but 2- they also decrease the potential for development of sooty mold from the honeydew by policing the aphids as they feed and not allowing the excrement to build up on plant surfaces. 

Aphids also work with the ants. Aphids can release pheromones to signal problems of which the ants will respond to, i.e. "fox in the hen house".  

Attached is a paper on ant attendance of aphids

There is a mutualistic relationship between ants and aphids. The ants give  protection for  the aphids on the plant from a number of predators and in return the aphids provide ants with food as honeydew as seen in the following link. The same for the mealy bug, .

https://www.youtube.com/watch?v=DnpJibC5iA0

https://www.youtube.com/watch?v=phHEsYPoTXs

Thank you Neelendra K. Joshi Adam Snyder Navaraj Upadhyaya and Hanna M. Madanat

 See this.

https://www.westcoastseeds.com/garden-resources/articles-instructions/do-ants-farm-aphids/ 

https://www.youtube.com/watch?v=0TJT90MJmQg

Quick note: The ants mostly harvest the sugary honeydew produced by these insects. However, if the ant colony needs a little more protein, then the hemipterans can be killed. The ants do not kill the colony, it is a selective harvest. There is a huge literature on ant-aphid interactions.

As mentioned by Mr Timothy, ants feed on the honey dew secreted by the aphids. Also, presence of large colony of ants is an indicator of aphid infestation.

similar to what has been said above, ants look for the sugary secretion and with some other hemipterans ants might move the young to the growing tips of plants where there is more nutrition.

Ants never feed on these types of sucking pest but they protect them for sake of the honey dew. This is also an example of mutual symbiosis.

At my doctoral exam it was absolutely required that the student answer one question with,

"It varies with the species." When I happened to say it I was immediately passed. 

You cannot answer a question about all ant-hemiptran associations with one answer. You can rarely answer anything with one answer. However, many the comments above are great. 

Dear Lewis,

I am a conservative teacher. Usually, I do not accept  answers like "it varies with the species." I need the examples. Without examples in the entomology – as I demand – general knowledge cannot be sufficient.  

Sometimes "it varies" is one of two possible responses. The other choice is to confront the person asking the question and demand that they rephrase the question into something that is answerable. For a graduate student, it is risky to tell a faculty member that they have asked a stupid question.

So there are many examples of ant-Hemiptera mutualisms. The ant-aphid mutualism is well studied for some species. I get some 10,000 hits in 0.07 seconds, and most of the top selections look like valid examples of different aspects of the mutualism. The mutualism has been studied for many decades, and I expect that a more careful search will turn up many articles not available to Google Scholar. There are many species of ant, and many species of Hemiptera that do not enter into this mutualism -- or a better phrasing is that there is no record of such mutualism for those species. It is further complicated in that not every colony of ant or every group of hemipteran will exhibit the mutualism and the fraction of colonies that do enter the mutualism is likely different for different niches. "This" species of ant when it has invaded households does not tend an aphid colony, while it typically does when it is found in more natural settings. More and more detail can be added, with more and more time spent in the literature asking this question.          The summary is "it varies," and the faculty member now has the option to ask a more specific question. Please focus your answer on Lasius niger tending Aphid fabae on tansy contrasted with Solenposis invicta tending Aphis gossypii on okra.

Dear András, 

Such questions are worded in such a way to ask for generalizations about that which cannot be generalized. Do ants, do birds, etc. are unanswerable; "varies with the species" is a wake up call. It has nothing to do with conservitave or liberal. Some liberal teachers also make sweeping generalizations. If a teacher wants examples, the teacher should ask for examples. Dr Ebert has answered your challenge more elequently above.

Thanks to all for your answer.

I think, ants feed upon the sugar substances secreted by aphids the so called honeydew and, even ants are always protect the aphids from other super natural enemies that will prey or parasitize for aphids in order to get the sugar substance.

Hi Milan

Many useful references on attachment 1

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFgg4MAM&url=https%3A%2F%2Fwww.planetnatural.com%2Fpest-problem-solver%2Fhouseplant-pests%2Fmealybug-control%2F&usg=AFQjCNH8YZwop-bJypCUWzxqGX5fn8ozJQ

2

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFgg-MAQ&url=http%3A%2F%2Fantark.net%2Fant-life%2Fant-feeding%2Fant-farming%2F&usg=AFQjCNHhvK6pYJoA1PkSiiaDAYTd8AdD2w

3

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFghGMAU&url=https%3A%2F%2Fwww.agric.wa.gov.au%2Fcontrol-methods-aphids&usg=AFQjCNF_jCcSVY_wsrO16ugNXvqJv-BLfg

4

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFghOMAY&url=http%3A%2F%2Fwww.bambooland.com.au%2Ftroubleshooting%2Fmealy-bugs-sooty-mould-and-ants%2F&usg=AFQjCNECOIQaHMRlvyXyrCdgRPKDW0tckg

5

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFghTMAc&url=http%3A%2F%2Fwww.practicallyfunctional.com%2Fget-rid-of-garden-pests-with-ladybugs%2F&usg=AFQjCNEoj59HFmW03b4hA8K3JdWAlYcLow

6

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFghZMAg&url=http%3A%2F%2Fwww.bromeliads.info%2Fcommon-bromeliad-pests%2F&usg=AFQjCNH5FEbGvx-LLEkbihXf_Kio2LzTnA

7

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFghfMAk&url=https%3A%2F%2Fwww.harvesttotable.com%2Fants_in_the_garden_ant_pestici%2F&usg=AFQjCNHcZuAHhoSyNhkPR3sYhUxigQRMhA

8

https://ucanr.edu/sites/tuolumne_county_master_gardeners/files/113803.pdf

9

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&cad=rja&uact=8&ved=0ahUKEwjVwuSnt7TWAhUBcBoKHUOxBmkQFghqMAs&url=http%3A%2F%2Fwww.aos.org%2Forchids%2Forchid-pests-diseases%2Fmealybugs.aspx&usg=AFQjCNF29R_--FnFr_vW8rb3Qkh7krjLJA

10

https://gardening.which.co.uk/hc/en-gb/articles/213972005-Controlling-ants-in-the-garden

11

https://blogs.scientificamerican.com/compound-eye/ants-run-vast-honeydew-ranches-just-under-our-feet/

12

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=13&cad=rja&uact=8&ved=0ahUKEwi04NeWubTWAhWmHJoKHW27CWM4ChAWCDEwAg&url=https%3A%2F%2Fbugsforbugs.com.au%2Fwhats-your-pest%2Fmealybugs%2F&usg=AFQjCNFlA336cOYlnp-oiNbpXZzxZ3qnKg

13

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=15&cad=rja&uact=8&ved=0ahUKEwi04NeWubTWAhWmHJoKHW27CWM4ChAWCD0wBA&url=https%3A%2F%2Fwww.orkin.com%2Fother%2Fmealybugs%2F&usg=AFQjCNGbJk-F0g27x5PkTR6y4ezlTvr4uQ

14

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=16&cad=rja&uact=8&ved=0ahUKEwi04NeWubTWAhWmHJoKHW27CWM4ChAWCEMwBQ&url=http%3A%2F%2Fwww.organicpathways.co.nz%2Fanswerfile%2Fquestion%2F78.html&usg=AFQjCNGfMdGCFsn7POkP0KZqRcXV-RVfrQ

15

https://books.google.com/books?id=RVHanXD-5-IC&pg=PA288&lpg=PA288&dq=ants+feed+on+aphids+and+mealybugs&source=bl&ots=0Maw_GnhNJ&sig=T98onkT5--vRFtfectkp7h_dyzY&hl=en&sa=X&ved=0ahUKEwi04NeWubTWAhWmHJoKHW27CWM4ChDoAQhIMAY

16

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=21&cad=rja&uact=8&ved=0ahUKEwj1j9PMubTWAhVISZoKHcsyD1M4FBAWCCYwAA&url=https%3A%2F%2Fhortnews.extension.iastate.edu%2F2008%2F2-20%2Fyellowants.html&usg=AFQjCNHKOf2dZUWhN68XxzGqH3z174v7Lw

17

https://books.google.com/books?id=Ql6Jl6wKb88C&pg=PA302&lpg=PA302&dq=ants+feed+on+aphids+and+mealybugs&source=bl&ots=qbvzG1AoGx&sig=5BKhcpBX1rgcM91yFVMghKCoocM&hl=en&sa=X&ved=0ahUKEwj1j9PMubTWAhVISZoKHcsyD1M4FBDoAQgsMAE

18

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=23&cad=rja&uact=8&ved=0ahUKEwj1j9PMubTWAhVISZoKHcsyD1M4FBAWCDAwAg&url=http%3A%2F%2Fwww.oregonlive.com%2Fhg%2Findex.ssf%2F2013%2F09%2Fgood_bugs_in_the_garden_--_and.html&usg=AFQjCNERJi4WIbr4VdrDOvsEUqsfLnkAhg

19

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=24&cad=rja&uact=8&ved=0ahUKEwj1j9PMubTWAhVISZoKHcsyD1M4FBAWCDcwAw&url=http%3A%2F%2Fdothan.weedmanusa.com%2FResources%2Flawn-care-news%2FAnts-on-my-%257B%257BZ_DisplayName%257D%257D-Lawn&usg=AFQjCNHi4S2jxPc85m2VqUulfgrE1njaww

20

https://books.google.com/books?id=v5We-H9B4kcC&pg=PA73&lpg=PA73&dq=ants+feed+on+aphids+and+mealybugs&source=bl&ots=p_JjalN0y8&sig=x2hd24DT2VC6wed9LlrA0oO6Dbc&hl=en&sa=X&ved=0ahUKEwj1j9PMubTWAhVISZoKHcsyD1M4FBDoAQg-MAU

No. Ants are seen in association with mealybugs and aphids, mainly for the highly nutritious honey due which is exuded from the aphids and mealy bugs

Ants do not feed aphids and mealy bugs but they are interested in the honeydew secreted by the aphids and other scale insects. However, I personally observed ants feeding on live Eretmocerus mundus (parasitoid) adults. This may be due to the fact that ants and parasitoids are in the same order of Hymenoptera but it requires research to confirm this.

This is a symbiotic relationship between ant and aphid/mealybugs. where ant provide protection from natural enemies and clean the colony and in return scales provide them sugar in the form of honey dew.