The Alms, the Monk and the Donor

The Alms, the Monk and the Donor

The result of making merit depends on the qualifications of the three components. These are the receiver, the alms and the donor. The result of making merit would depend very much on how the alms-receiver is. If we offer alms to a monk, the purer and more observant the monk is, the more merit we will receive.
If we give food as an alms to animals, in terms of merit, we will receive very little. The reasons is that an animal is in a lower position than human beings. The animals cannot observe religious precepts. Buddhists believe that observing precepts is moral training or a purification process. For the same reason, if we give alms to those people who do not have the 5 precepts in mind, for example mischievious people, we will receive very little merit, but more than offering to animals.
We will gain more merit if the receiver observes the 5 precepts (refrain from killing, stealing, from sexual misconduct, from lying and from taking intoxicants). We would then gain even more merit if they observed 8 or 10 precepts. And of course even more if it was a monk who observes his 227 precepts completely.
But, we also have to be aware that the alms we offer is clean. For example, if you offer something that doesn't belong to you. If you are immoral as well and the monk doesn't observe properly all 227 precepts, then you won't receive merit. Only if you are morally clean and have good intentions, and so is the monk who observes his religious precepts perfectly, then this alms-giving will result in a full and perfect merit.
Main Source: How to get Good Results from Making Merit