Transactions appearing out of nowhere when running monero in local network

Question

I've followed the instructions here to run monerod and monero-wallet-cli only on localhost. After I started mining, I noticed transactions showing up in my wallet:

Height 350, txid <fe0a6cd86e9c3f65b...b2bfc0aec75c>, 0.000314995907, idx 0/0
Height 350, txid <fe0a6cd86e9c3f65b...b2bfc0aec75c>, 0.006000000000, idx 0/0
Height 350, txid <fe0a6cd86e9c3f65b...b2bfc0aec75c>, 0.080000000000, idx 0/0
Height 350, txid <fe0a6cd86e9c3f65b...b2bfc0aec75c>, 0.500000000000, idx 0/0
Height 350, txid <fe0a6cd86e9c3f65b...b2bfc0aec75c>, 7.000000000000, idx 0/0
Height 350, txid <fe0a6cd86e9c3f65b...b2bfc0aec75c>, 10.000000000000, idx 0/0
Height 351, txid <8de34f3a537e84a65...93591aab2196>, 0.000298224290, idx 0/0
Height 351, txid <8de34f3a537e84a65...93591aab2196>, 0.006000000000, idx 0/0
Height 351, txid <8de34f3a537e84a65...93591aab2196>, 0.080000000000, idx 0/0
Height 351, txid <8de34f3a537e84a65...93591aab2196>, 0.500000000000, idx 0/0
Height 351, txid <8de34f3a537e84a65...93591aab2196>, 7.000000000000, idx 0/0
Height 351, txid <8de34f3a537e84a65...93591aab2196>, 10.000000000000, idx 0/0
Height 352, txid <b990c46eec87c033a...cdb3a24465d2>, 0.000281452690, idx 0/0
Height 352, txid <b990c46eec87c033a...cdb3a24465d2>, 0.006000000000, idx 0/0
Height 352, txid <b990c46eec87c033a...cdb3a24465d2>, 0.080000000000, idx 0/0
Height 352, txid <b990c46eec87c033a...cdb3a24465d2>, 0.500000000000, idx 0/0
Height 352, txid <b990c46eec87c033a...cdb3a24465d2>, 7.000000000000, idx 0/0
Height 352, txid <b990c46eec87c033a...cdb3a24465d2>, 10.000000000000, idx 0/0

And my wallet had a balance:

Untagged accounts:
          Account               Balance      Unlocked balance                 Label
 *       0 55yRTv    11484.115773696844    10446.794283469116       Primary account
----------------------------------------------------------------------------------
          Total    11484.115773696844    10446.794283469116
Currently selected account: [0] Primary account
Tag: (No tag assigned)
Balance: 11484.115773696844, unlocked balance: 10446.794283469116

Where are these transactions coming from? I've not made any transactions and monerod is only communicating to the other monerod node running on the same machine.

Answer 1

Blocks get mined every 2 minutes on average regardless if there are transactions or not. Your node is the one mining them. You are getting the mining reward.

Answer 2

They are the coinbase transactions or block reward from your mining. See moneropedia

Answer 3

Monero, like Bitcoin, incentivizes miners with a block reward, so you get some amount of monero when you mine a new block. Those coinbase transactions do not have any non-placeholder inputs, just outputs.